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Learn about networking standards and the seven layers of the Open Systems Interconnected (OSI) model - Application, Presentation, Session, Transport, Network, Data Link and Physical. Based on the 2020 Eduqas (WJEC) GCSE specification. 3.6: 7-Layer OSI Model Exam Board: Eduqas / WJEC Specification: 2020 + What are networking standards? Networking standards are rules that allow computer systems to communicate across networks . Standards have been created to ensure devices can exchange data and work together . What is the 7-layer OSI Model? The OSI ( Open Systems Interconnection ) model is split into 7 layers . The model is used to visualise the different parts of a network as each of the seven layers has a specific role . Splitting a network design into layers is beneficial to programmers as it simplifies design , making it easier to modify and use . Each layer has a certain purpose and is associated with different protocols . The seven layers are explained below: 7 Allows humans and software applications to use the network e.g. browsers (HTTP /HTTPS ) and email (SMTP ) and file transfer (FTP ). 6 The purpose of the presentation layer is to display data in a standard format that other devices can accept and understand . 5 The session layer establishes a connection between computers allowing data to be sent between them. Data can be synchronised in each session to allow for efficient data transfer . 4 TCP breaks the data down into data packets . This layer makes sure the data is sent and received in the correct order and reassembled at the destination without errors. 3 IP is responsible for addressing and routing data packets . The optimal route for the data to take is calculated in this layer. Also known as the 'Internet Layer '. 2 Ethernet sets out the format of data packets . This layer handles transmission errors and passes data to the physical layer . 1 This layer converts the data packets into bits so they can be transferred across a physical connection using routers and switches . Q uesto's Q uestions 3.6 - 7-Layer OSI Model: 1a. What are networking standards ? [ 2 ] 1b. Describe why network designs are split into layers . [ 2 ] 2. Create a diagram similar to the one above and describe each layer of the OSI Model. [ 14 ] 3. Look at the statements below and name the layer that is being described: a. This layer ensures data packets are sent and received correctly. b. This layer checks for errors in transmission and sets out the data packet format. c. This layer displays data in a format that can be understood. d. This layer allows software like web browsers to interact with the network. e. This layer transfers bits across a connection using routers. f. This layer establishes a connection between computer systems. g. This layer uses addresses to ensure data packets take the correct route. [ 7 ] 3.5 - Protocols Theory Topics 3.7 - The Internet

Learn about the purpose, characteristics, advantages, disadvantages, examples and client requirements of application software types, including off-the-shelf, custom off-the-shelf and bespoke software. Resources based on Unit F160 (Fundamentals of Application Development) for the OCR Cambridge Advanced National in Computing (H029 / H129) AAQ (Alternative Academic Qualification). Qualification: Cambridge Advanced National in Computing (AAQ) Unit: F160: Fundamentals of Application Development Certificate: Computing: Application Development (H029 / H129) 1.3.3 - Application Software Types Watch on YouTube : Off-the-Shelf Software Custom Off-the-Shelf Software Bespoke Software There are three application software types you need to know : Off-the-shelf software Custom off-the-shelf software Bespoke software For each software type , you need to know : Its purpose and common characteristics . The advantages and disadvantages of using the software. How client requirements affect the selection of that software. Application Software Types Off-the-Shelf Software Off-the-shelf software is pre-made and available for anyone to buy and use . It is designed for general users and common tasks . It is pre-developed and ready-made with standard features for a wide audience , not custom-built for a specific user. Its purpose is to provide a cost-effective , quick-to-deploy solution for popular applications . Custom Off-the-Shelf Software Custom off-the-shelf software is pre-built like regular off-the-shelf software , but can be slightly customised to meet specific user needs . It offers a balance between quick setup and limited personalisation . It supports configurable features such as add-ons , plugins or modules to extend or adapt functionality while the base software remains maintained and updated by the original developer . Bespoke Software Bespoke software is designed and built specifically for one organisation or user . It fits their exact needs but usually costs more and takes longer to develop . An example is a bespoke system developed for a specific bank with custom software to handle financial regulations , unique products and security needs . Other examples include government systems , hospital patient management and air traffic control . Q uesto's Q uestions 1.3.3 - Application Software Types: 1. Explain the differences in purpose and characteristics between off-the-shelf and custom off-the-shelf software. [4 ] 2. A dental surgery needs new software to manage its customer bookings . Justify which application software type they should use and why . [4 ] 3. Describe two advantages and two disadvantages of the three application software types on this page. [ 12 ] Off-the-shelf software gets its name from the days when software like Microsoft Word was sold on physical discs in shops , for customers to take off the shelf and install at home . D id Y ou K now? 1.3.2 - Software Categories Topic List 2.1 - Software Development Models

Learn about the decomposition methods used in project planning such as abstraction, pattern recognition, modularisation (top down and bottom up) and parsing of requirements. Based on Unit F160 (Fundamentals of Application Development) for the OCR Cambridge Advanced National in Computing (H029 / H129) (AAQ - Alternative Academic Qualification). Qualification: Cambridge Advanced National in Computing (AAQ) Unit: F160: Fundamentals of Application Development Certificate: Computing: Application Development (H029 / H129) 4.3 - Decomposition Methods Watch on YouTube : Abstraction Pattern Recognition Modularisation Parsing of Requirements Decomposition methods break complex problems or systems into smaller , more manageable parts . This makes development easier to plan , understand and implement . Decomposition also helps reduce errors and improve efficiency , as individual tasks can be more easily tested and debugged. For each of the four decomposition methods ( abstraction , pattern recognition , top-down and bottom-up modularisation and parsing requirements ) you need to know when each method is suitable to use , its advantages and disadvantages , how client requirements affect their selection and how they can be used to visualise application designs . Decomposition Methods Abstraction Abstraction is the process of simplifying a problem by ignoring irrelevant data and focusing only on the most important details . It is used in the early stages of design or planning , when managing complexity in large systems and when creating reusable components . Pattern Recognition Pattern recognition is used to identify similarities or trends in problems or client requirements . This allows for the reuse of existing components and aids in finding solutions for common issues . It is used during the planning or analysis phases and when dealing with similar tasks , inputs , outputs or processes . Modularisation Modularisation refers to the individual components that make up a larger project . In top-down modularisation , a larger system is broken down from a general overview into its most specific parts . The purpose of bottom-up modularisation is to build the system starting with the smaller , detailed components and combining them into larger subsystems . Parsing of Requirements To parse requirements means to systematically break down and analyse client requirements into actionable tasks or functions . It is used at the start of a project to ensure shared understanding between development teams and clients . Q uesto's Q uestions 4.3 - Decomposition Methods: 1. Explain the differences between top-down and bottom-up modularisation . [4 ] 2. Explain when abstraction would be an appropriate decomposition method to use. [3 ] 3. What are the advantages and disadvantages of parsing requirements ? [ 4 ] 4. Give one way each decomposition method can be used in software application development . [ 4 ] Alan Turing and his team used pattern recognition to analyse recurring sequences in encrypted German messages , helping to break the Enigma code , which was a major factor in the Allies’ victory in World War II . D id Y ou K now? 4.2 - Client Requirement Specs Topic List 5.1.1 - Human-Computer Interaction

Learn about crucial laws in place to protect data and privacy, including the Data Protection Act (2018), Computer Misuse Act (1990), RIPA (2000) and the Freedom of Information Act (2000). Based on the 2016 OCR Cambridge Technicals Level 3 IT specification for Unit 2 (Global Information). 4.1 - UK Legislation Specification: 2016 - Unit 2 Exam Board: OCR There are many types of legislation - laws that have been written into use - that concern data storage, protection and the use of information. In an exam, the year the law was introduced must be stated . In 2018 the European Union introduced GDPR (General Data Protection Regulation ) to protect the privacy of data for people in the EU. The UK matched this by updating the Data Protection Act introduced in 1998 to become the Data Protection Act (2018) . This act protects the data of individuals that is stored on computers and processed by organisations. How the Data Protection Act works: Each person who has their data stored is known as a data subject . An employee within an organisation must be appointed as a data controller and it is they who are responsible for registering with the Information Commissioner . The Information Commissioner is the person in the UK who is responsible for managing several laws , most significantly the Data Protection Act. When registering with the Information Commissioner, the organisation's data controller must be clear on exactly: What information they are collecting, Why it is being collected, What the data will be used for . The six principles of the Data Protection Act (2018) state: 1. Data must be collected lawfully and processed fairly. 2. Collected data must only be used for the reasons specified. 3. Data must be relevant and not excessive. 4. Data must be accurate and up-to-date. 5. Data must not be stored for longer than necessary, 6. Data must be stored and processed securely. Actions organisations must take to stick to the Data Protection Act (2018): The company must appoint and register a member of staff to act as the organisation's data controller . The data controller is responsible for communicating with the Information Commissioner and ensuring the principles of the DPA are not broken . There must be strong security measures in practice to protect data from being accessed or transferred without authorisation . This could be in the form of physical or digital protection methods enforced by the company. Staff should be trained so that they are clearly aware of their responsibilities and each principle is adhered to. For example, they should know that data can only be used for the reasons specified when it is collected and should not be passed to others without the permission of the data subject. Data subjects should be given the opportunity to alter their data and make changes if it is incorrect . Data should be deleted when it is no longer needed , so organisations should periodically assess both the accuracy and relevance of storing each data subject's information. Data subjects have the right to make a Subject Access Request (SAR ) and receive a copy of the data which is stored about them. Companies must abide by this request by verifying the user's identify and presenting the data to them securely . Rights of data subjects: Under the Data Protection Act, individuals have a right of access to any information that is stored about them by public bodies . If an individual wishes to access their data they must submit a Subject Access Request (SAR ) which results in the following steps: The organisation's data controller must be written to and told exactly what information is required to access. An administrative fee should be paid to the organisation (but only if the request requires excessive efforts to fulfil ). The organisation must provide the requested information within 40 days . The individual must verify their identity using appropriate ID because only the data subject can request their data . Computer Misuse Act (1990) This act was introduced as computers became cheaper and more common at home and work . The act attempts to stop and punish those who use computers inappropriately . Breaking any of the three principles could result in fines and a jail sentence but only if it can be proved it was done on purpose and not by accident. The Computer Misuse Act (1990 ) includes three main principles : 1. No unauthorised access to data. Example: Hacking a computer system. 2. No unauthorised access to data that could be used for further illegal activities. Example: Accessing personal data to use as blackmail or identity theft. 3. No unauthorised modification of data. Example: Spreading a virus to change data. Data Protection Act (2018) / GDPR Freedom of Information Act (2000) This act allows people to request public authorities to release information . Public authorities include local councils , government departments , universities and hospitals . A freedom of information request must be formally submitted in a letter or email and a reply from the organisation is required within twenty days of receiving the request. A simple freedom of information request might be the average response times of the local ambulance service in the past year. Certain requests will not be accepted , such as if processing the request would be too expensive or if it involves sensitive information protected by the Data Protection Act (2018 ). Regulation of Investigatory Powers Act (2000) This act (often shortened to RIPA ) was introduced in response to the increase in both criminal and terrorist activities on the internet, it is used to monitor and access online communication of suspected criminals . If criminal activity is suspected by an individual then this act grants the following powers : Internet Service Providers (ISPs) must provide access to the suspect's online communication , such as emails or social media. Locked or encrypted data may be accessed such as online messages. ISPs could install surveillance equipment or software to track the suspect's online activity . Surveillance may take place to physically track the suspect , e.g. in private vans or by undercover officers in public spaces. Access must be granted to personal information . This act became controversial as its use widened and local councils were using it for minor offences - a Scottish council used the act to monitor dog barking and a council in Cumbria gathered video evidence about who was feeding pigeons . The act has since been changed to only allow the surveillance of crime suspects . Copyright, Designs & Patents Act (1988) This act makes it a criminal offence to copy work that is not your own without the permission of the creator or the copyright holder. This can refer to text, images, music, videos or software. Owning the copyright of an image might not prevent others from copying and using it but this act means that the owner can bring legal proceedings in court to those who have stolen their work . Creators of copyrighted work can take ownership of their work and control how it is used . Others must ask for permission to use the work otherwise the copyright holder can ask for it to be removed or demand a fee for its use . This act specifically prohibits the following actions: Making copies of copyrighted material to sell to others . Importing and downloading illegally copied material (except for personal use). Distributing enough copyrighted material to have a noticeable effect on the copyright holder . Possessing equipment used to copy copyrighted material , as part of a business. Information Commissioner's Office (ICO) Codes of Practice Protection of Freedoms Act (2012) There are seven sections to this act, revolving around the protection of personal data . It was introduced because there was little legislation about biometric data , and to update older laws . IT-related sections are summarised below: Part 1 - States how biometric data (e.g. fingerprints and DNA) is stored, handled and collected. For example, parents must give consent before their child gives biometric data to a school. Also, biometric data for suspects of minor offences is deleted after the case is closed. Part 2 - Creates new regulation for CCTV and ANPR (automatic number plate recognition) use. Part 5 - The Disclosure & Barring Service (DBS) was created to run background checks on anyone wanting to work with children or vulnerable people. Part 6 - Extends the Freedom of Information Act (2000) allowing for wider requests to be made . The information commissioner is the senior government official in charge of the country's freedom of information requests and the protection of personal data . The Information Commissioner's Office describes itself as "The UK’s independent authority set up to uphold information rights in the public interest, promoting openness by public bodies and data privacy for individuals". The ICO publishes codes of practices about various data protection and privacy topics , usually related to explaining the Data Protection Act . For example, the ICO has a code of practice regarding how organisations should share data and another code of practice about the use of CCTV . The ICO offers help and support to both individuals (such as giving access to students to their exam results) and organisations (such as support with legal electronic marketing). Privacy and Electronic Communications Regulations (2003) This law (which was updated in 2011 ) regulates how organisations can communicate with individuals . Companies must stick to the following rules: It is an offence to directly contact an individual unless they have specifically opted-in to receive communication. This is commonly managed by using tick boxes on online stores where you must opt-in to receiving promotional material. Companies must clearly state who they are when contacting customers, such as displaying the phone number when calling - and not 'hiding' the number. Organisations must explain how cookies are used on their website . Companies must only contact customers through communication channels that the customer has previously permitted . This can be done with tick boxes when signing up. Customers can select or de-select methods such as email , phone calls and text messages . The Information Commissioner's Office (ICO) is responsible for this regulation and can fine companies that commit unsolicited communication up to £500,000. It is the customer who benefits and is protected by this regulation. Equality Act (2010) The government states that "The Equality Act legally protects people from discrimination in the workplace and in wider society." Discrimination because of protected characteristics such as gender , race , religion , age and disability are specifically punishable by legal action. The aim of the act is to end discrimination in the workplace and open up fair opportunities for every employee regardless of behavioural or physical characteristics that are outside of their control . Within a company, the Equality Act protects staff by stating protected characteristics should not be a factor in an employee's promotion or change of role. Information must be presented in a format accessible to all staff . Q uesto's Q uestions 4.1 - UK Legislation: 1. Create a flashcard or PowerPoint slide for each legislation above. Explain the purpose of the legislation , its main principles and whom it affects . [5 each ] 3.6 - Information Systems Topic List 4.2 - Global Legislation

Learn about network operating systems, open source operating systems and proprietary operating systems. Resources based on Unit F160 (Fundamentals of Application Development) for the OCR Cambridge Advanced Nationals in Computing (H029 / H129) AAQ (Alternative Academic Qualification). Qualification: Cambridge Advanced National in Computing (AAQ) Unit: F160: Fundamentals of Application Development Certificate: Computing: Application Development (H029 / H129) 1.2 - Operating Systems Watch on YouTube : Network Operating System Open Operating System Proprietary Operating System An operating system is software that manages the resources of a computer system , such as memory , users and files . It also provides a user interface so that humans can interact with the device's hardware . An operating system allows application software to be opened and run . There are three types of operating system that you need to know - network , open and proprietary . Operating Systems Network Operating System (NOS) A network operating system (NOS ) is software that manages network resources and allows computers to communicate over a network . Windows Server , developed by Microsoft , is an example of a network operating system . Characteristics of a Network Operating System Allows for the centralised management of users , data and security across multiple devices on a network . Enables resources such as files , applications and printers to be shared over the network . Manages user authentication and permissions control . Oversees remote access and system monitoring tools . The main type of device that uses a NOS is a server . Other devices, such as desktops or laptops , connect to the server to access shared resources . Windows Server is an example of a popular NOS . Advantages of a Network Operating System Administrators can manage users , files and security on a network from one central location . Resources such as files , printer access and applications can be shared across the network . Access levels can be controlled and user authentication helps protect data . An NOS is scalable - more devices and users can be added as needed . Central servers managed by a NOS make it easier to back up and restore important files . Disadvantages of a Network Operating System Purchasing a NOS and maintaining the servers it runs on can be expensive . Setup and management is complex and may require skilled administrators . If the main server running the NOS fails , connected computers may lose access to resources . Heavy traffic or poor configuration could slow the network down . Who uses a Network Operating System? Application developers can use a NOS to build , test and manage apps that work across networks , such as web applications , multiplayer games or cloud tools . This type of operating system is also used by organisations that need to manage multiple devices , users and resources efficiently across a network , such as a small business or a school . Open Operating System An open operating system is open-source , meaning its source code is freely available for anyone to view , modify and distribute . Source code is the original set of instructions written by a programmer using a high-level language such as Python , Java or C++ . Characteristics of an Open Operating System Users have access to the source code and can see how the OS works . The source code can be modified to suit the specific needs of the user . Development and maintenance may be led by an online community . An open OS is usually free with no licensing costs for most versions. Linux is an example of an open operating system . Android is technically an open-source OS , but most commercial Android devices (like Google Pixel phones ) include proprietary components (like Google Docs or Gmail ), which makes the full system not completely open source . Advantages of an Open Operating System It is usually free to use , modify and distribute the source code . Because the source code can be seen and modified , this type of OS is flexible and customisable . There may be updates from an online community maintaining and improving the software . Promotes experimentation to learn how systems work and try new ideas . Disadvantages of an Open Operating System Programming knowledge and skills are required to modify the source code . There may be security risks if someone edits the source code and redistributes it with malicious code . There will be less official support compared to a proprietary operating system . Some proprietary applications (like Microsoft Access for databases) will only work on a proprietary OS (like Windows ). Who uses an Open Operating System? App developers would use an open OS when the device their application will be used on is not tied to a specific proprietary system (like Windows or MacOS ). For example, a charity making a free educational app for developing countries would choose an open OS so it can run on low-cost , older smartphones . It can be customised and tested on a range of devices . Applications for specific single-purpose systems would also use an open OS , such as an information terminal in a museum . Linux could be used to develop a simple user interface and remove unnecessary features . Proprietary Operating System A proprietary operating system is software that is owned by a company or individual and the source code is not accessible for users to view , modify or distribute . Users must typically buy a licence or agree to the terms of use . Characteristics of a Proprietary Operating System The source code is hidden from the user and cannot be legally modified . A paid licence or subscription is usually required to use the software . It may be maintained and updated by the developer(s) who own it . Only the developer controls updates and the features that are added or fixed . Examples include Microsoft Windows (e.g. Windows 11 ), macOS (for Apple desktops and MacBooks ), iOS (for iPhones ) and iPadOS for iPads ). Advantages of a Proprietary Operating System There is an expectation that it is user-friendly and has been well tested . There may be official support and regular updates for improvements and bug removal . A proprietary OS has a high compatibility with proprietary software such as Microsoft Office or Adobe editing apps . The OS is expected to be stable and secure , with access restricted to system files . Disadvantages of a Proprietary Operating System A paid licence to use the OS is often required , which may be expensive . There is limited customisation for users as the source code cannot be seen or modified . Users rely on the vendor (developer ) for updates and bug fixes . Some proprietary OS are designed to only work on specific hardware (such as iOS only working on iPhones ). Who uses a Proprietary Operating System? App developers will need to use a proprietary OS if they are developing applications for a device that requires a specific proprietary OS , for example if they are creating a game for iPhones , they will need to use iOS . A company designing a finance application on desktops with Microsoft Access and Microsoft Excel must use a proprietary OS like Windows so that it can be integrated with these other types of proprietary applications . Q uesto's Q uestions 1.2 - Operating Systems: 1. What is an operating system ? [2 ] 2. For each of the three types of operating systems , create a poster , information sheet or factfile which includes the following information : Characteristics Advantages Disadvantages Example of how it could be used [10 per OS ] Windows 11 is Microsoft's current operating system . Windows 1.0 was their first release, introduced in 1985 and included basic versions of Calculator , Notepad and Paint . D id Y ou K now? 1.1 - Programs & Applications Topic List 1.3.1 - Application Types

Learn about sorting algorithms - merge and bubble sort - and searching algorithms - linear and bubble search. Based on the 2020 Eduqas (WJEC) GCSE specification. 8.4: Sorting & Searching Algorithms Exam Board: Eduqas / WJEC Specification: 2020 + Merge Sort Merge sort is a sorting algorithm based on the idea of ‘divide and conquer ’. A merge sort divides a list into half , again and again until each data item is separate . Then the items are combined in the same way as they were divided , but now in the correct order . When the individual lists are all merged together as one list again, then the data is in order and the algorithm will end . Bubble Sort This algorithm is based on the comparison of adjacent data elements . Data elements are swapped if they are not in the correct order . A bubble sort is not suitable for large sets of data. Linear Search A linear search is the most simple search algorithm. Each data item is searched in order from the first value to the last as if they were all laid out in a line . The list does not have to be in any order before it is searched . This search is also known as a sequential search because the list is searched in a sequence from start to end. For large lists , this search is not very efficient . Binary Search A binary search is a much more efficient searching algorithm as it generally searches through fewer data and is often much quicker - especially for large data sets. In a binary search, the middle point of the data is selected with each iteration and many data items can be ignored. However, the list of data must already be sorted in order before a binary search can take place. Q uesto's Q uestions 8.3 - Searching & Sorting Algorithms: Linear Search Explain step-by-step how the number 8 would be found in the following list using a linear search : 12, 5, 3, 2, 8, 19, 14, 6 [4 ] Binary Search Explain step-by-step how the number 2 would be found in the following list using a binary search : 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 [6 ] Merge Sort Explain step-by-step how a merge sort would sort the following list of numbers: 4, 8, 5, 1, 3, 6, 7, 2 [6 ] Bubble Sort Explain step-by-step how a bubble sort would sort the following list of numbers: 3, 2, 6, 4, 1, 4 [6 ] Watch on YouTube Watch on YouTube Watch on YouTube Watch on YouTube 8.3 - Writing Algorithms Theory Topics 8.5 - Validation & Verification

Learn about different input and output devices, RAM (random access memory) and ROM (read only memory) and storage devices, including solid state, magnetic and optical types. Based on the OCR H446 Computer Science A-Level specification. Exam Board: OCR A-Level 1.3 - Input, Output & Storage Specification: Computer Science H446 Watch on YouTube : Input & output devices Storage devices RAM & ROM Virtual storage This topic covers the internal and external devices required to input data into computer systems , output from them and store data for both temporary and long-term use . Input & Output Devices Input devices , such as a keyboard , mouse , microphone or sensor , allow data to be entered into a computer system for processing . Input can be manual (e.g. typing on a keyboard ) or automatic (e.g. a temperature sensor taking readings ). Output devices , such as monitors , printers and speakers , present the results of processing in a form understandable to humans . Input and output are not limited to text - they may also be visual , audio or tactile (e.g. braille displays or printed paper ). Storage Devices Secondary storage is non-volatile storage used to permanently hold programs and data when not in use by the CPU . There are three types : Magnetic storage uses magnetised patterns on a disk or tape (e.g. hard disk drives or magnetic tape ) to store large amounts of data for a low cost per gigabyte . Solid-state storage uses flash memory with no moving parts (e.g. SSDs and USB drives ), making it very fast , durable and portable . Because there are no moving parts, it is the fastest to access data . Optical storage uses lasers to read and write data as pits and lands on a disc surface (e.g. CDs, DVDs, Blu-ray). Discs are cheap to mass produce , but they are not durable , slow to access and have a low capacity . RAM & ROM Primary storage is low-capacity , internal storage that the CPU can directly access . There are two types: Random Access Memory (RAM ) is volatile storage that temporarily holds both programs and data currently in use , including the operating system . It can be read from and written to , but all contents are lost when the power is turned off . Read Only Memory (ROM ) is non-volatile storage that normally cannot be changed . The contents of ROM are saved when the power is turned off . ROM stores the BIOS and firmware , including the instructions needed to boot the computer when it is switched on . Virtual Storage Virtual storage is the separation of logical storage from physical storage , such as when data is stored remotely and accessed over a network instead of being kept locally . A common example is cloud storage , where data is held on remote servers and accessed via the internet . Benefits are that it is scalable , enables easy collaboration , provides automatic backup and saves local storage space . Drawbacks include that it relies on a stable internet connection , poses security risks and reduces user control over data . Q uesto's K ey T erms Input & Output Devices Secondary Storage: magnetic, solid state, optical, portability, capacity, cost (per GB), access speed, reliability, durability, power consumption Primary Storage: RAM, ROM, volatile, non-volatile Virtual Storage: cloud storage D id Y ou K now? The first commercial hard disk drive , the IBM 305 RAMAC (released in 1956 ), was the size of two fridges , weighed around a tonne , and stored just 5 MB of data - about the same as one .mp3 song . 1.2 - Types of Processor A-Level Topics 2.1 - Systems Software

Learn about the negative impacts that data loss will have on an organisation including reputation loss, fines and possible bankruptcy. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification for Unit 2 (Global Information). 6.3 - Impacts Exam Board: OCR Specification: 2016 - Unit 2 If a risk to data (see 6.2 ) occurs then there are a number of different impacts that may consequently negatively affect an organisation . Loss of Intellectual Property 'Intellectual property ' refers to anything that an organisation or individual has designed, developed or created themselves . For an individual, this could be a manuscript , artwork or piece of music . For an organisation, it could be primary data they have collected, blueprints for an upcoming design or a report following data analysis. The impact of having intellectual property lost depends on the property itself and how easy it would be for the victim to recreate or recollect the data . Competitors that stole intellectual property could use it at their advantage. Also, the effect of an upcoming announcement to the public would decrease if it was leaked ahead of time. In 2017 HBO suffered large property leaks when Game of Thrones episodes were stolen before air date resulting in pirated versions appearing online well before they were due to be shown on TV. Loss of Service and Access If usernames and passwords are stolen then individuals may be unable to access services that they have paid for, an example being if WiFi details were stolen so that a hacker can access the internet using someone else's account. If a hacker is permitted access to a system they can change the account settings such as the password to lock out the original owners of that account, leaving them without access. Other services can be targeted with malicious attacks like a DDOS attack so that users cannot log into a web page or online service. If users cannot access an account they may use alternative methods and providers , such as avoiding one type of cloud storage provider that has let them down and choosing another. Breach of Confidential Information Confidential information is of a highly sensitive nature and could lead to other negative impacts if it got into the hands of unauthorised people . Confidential information, such as medical histories, should be stored securely with multiple physical and logical protections in place to ensure that it keeps its integrity . If confidential information was breached then it could lead to a loss of reputation as the holder would be regarded as ineffective at protecting the data . Legal consequences would also follow as the Data Protection Act ( 2018 ) would be broken : fines, court cases and even imprisonment would be possible further impacts. An organisation would expect to see penalties from the Information Commissioner's Office (ICO) if they failed to protect personal details by breaking the DPA . Loss of Third Party Data Many organisations will store data not only for their own purposes but for other individuals and businesses too; a key example being cloud storage providers . Users can store data on public cloud services such as Google Drive or DropBox and access their information using the internet from any networked device they please. If services like cloud storage services are hacked or taken offline (e.g. because of an attack or network problems) and data is lost then customers, especially those that pay, will be furious. This will lead to a loss of reputation, trust and even legal proceedings if personal and sensitive data is lost. Larger businesses will use private cloud storage, hosted in data centres that they maintain themselves, to avoid relying on third parties . Loss of Reputation Organisations spend years to build up a reputation where customers trust them and want to use their products or services. Data loss can immediately destroy that reputation and cause once-loyal customers to look elsewhere and choose their competitors . Failing to keep data safe means that an organisation has been unable to follow their legal and moral duty of keeping information secure and could lead to a loss of trade , resulting in reduced earnings and sales . Identity Theft If an individual's personal information is stolen by attackers then one impact is identity theft - when the attacker uses the victim's data for fraud or impersonation . Identity theft can lead to financial loss to the victim if loans , products or services are purchased in their name . The victim may have to contact their bank and other organisations to cancel transactions and there is no guarantee their money will be returned. Credit checks may be affected, leading to future financial difficulty for the victim. Threat to National Security If data of a classified nature (such as military arrangements, security weak-points or upcoming government plans) is lost and falls into the hands (most probably by hacking) of those who intend to bring harm to the country then the consequences can be disastrous. Spies of foreign countries or terrorists could use classified information to target vulnerable locations or events resulting in casualties. Threats could also be economic in nature if large amounts of money are stolen or redirected to malicious bodies. Recent Examples of Security Failure Q uesto's Q uestions 6.3 - Impacts: 1. Describe how each of the impacts above could affect a bank storing large amounts of customer data including financial records. [12 ] 2. Research three recent hacking examples . For each situation describe the impacts that occurred as a result of data loss . [12 ] Click the icons to read BBC News articles about recent examples of hacks and security breaches . Virgin Media Boots Marriott Hotels Facebook Messenger 6.2 - Risks Topic List 6.4 - Protection Measures

Learn how to comment in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. top Python 1b - Commenting Writing Comments To annotate your work, you can write a comment using the # symbol. Comments are ignored when you run the program and they are not printed . #This is a comment! print ( "Welcome to Python!" ) #The code above prints a nice greeting = Welcome to Python! Programmers use comments to explain to other people (and themselves) what different sections of code do . With massive programs, comments are vital; otherwise, it would be too confusing, especially after returning from a few weeks or months on a different project. If you are creating a Python project for school (or A-Level Computer Science coursework), you will need comments to explain your code and prove you have written it yourself. Comments over Multiple Lines Have a lot to say in one comment? Use three apostrophes ( ”’ ) at the start and three more at the end of your comment like below: '''This is a comment that I have spread out over more than one line''' print ( "Hello! How are you?" ) Top Tip: Use multi-line comments when testing a program to ‘blank out’ sections that you know work fine and only focus on one part at a time. Commenting Task 1 (Day of the Week & Weather) On line 1 write a single-line comment ( use # ) to state that your program will print the day of the week. On line 2 print the current day of the week. On lines 3, 4 and 5 write a multi-line comment (use ''' ) about the weather today. Remember comments won't be printed so only the day of the week should be output. Example solution: Wednesday ⬅ 1a - Pri nting 1c - Crea ting Variables ➡

Learn about the advantages and disadvantages to individuals and organisations when using the internet. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification for Unit 2 (Global Information). 1.7 & 1.8 - Internet Pros & Cons Exam Board: OCR Specification: 2016 - Unit 2 The internet has become easier and cheaper to access since the mid 1990s and today it is almost taken for granted. The rise of the internet, and the services it provides, has lead to advantages and disadvantages for both individuals and organisations . Advantages for Individuals Increased speed of personal communication Allows for instant messaging, emails and video chats across the world. Easy access to information The internet has free resources such as CSNewbs and Wikipedia, plus academic journals for research & study. 24/7 access to services Shopping, browsing and banking can be completed when convenient for the user. Social interaction with others Social media, discussion forums and online games provide entertainment and social interaction. Disadvantages for Individuals Potential for identity theft Uploading personal data and storing sensitive information risks hackers obtaining and utilising it. Cost of connection & services Internet service providers (ISPs) charge a monthly fee and equipment like a router needs installation. Cyberbullying & trolling The abuse of others on social media is possible. Anonymisation makes it harder to catch offenders. Spreading misinformation 'Fake news' or biased information can be easily spread on social media and lead to incorrect assumptions. Source of distraction Staff and students may neglect their work and study for entertainment or social media. Advantages for Organisations Share data quickly globally Files and information can be sent instantly to locations across the world. Cloud storage can store data. Online services always available E-commerce businesses can operate 24/7 globally, permit users to browse and accept payments. Easy internal communication Staff can use emails, video calls or instant messages to communicate. Open up the workplace Staff can work from home, on the commute to/from work and outside of the office. Disadvantages for Organisations Malicious attacks & threats Websites can be hacked / taken offline with DDoS attacks. Data can be stolen or corrupted. Cost of maintaining services Most companies require an IT department to oversee device installation and maintenance. Reputation and controversies Companies that leak data will damage their reputations. Social media posts could backfire. Q uesto's Q uestions 1.7 - Internet Pros & Cons: 1. List 5 points for the following categories (you may need to include researched / your own points for some): a. Advantages of the internet for individuals [5 ] b. Disadvantages of the internet for individuals [5 ] c. Advantages of the internet for organisations [5 ] d. Disadvantages of the internet for organisations [5 ] 1.6 - Information Formats Topic List 2.1 - Information Styles

Learn about data types (integer, real, character, string, Boolean), positive and negative binary, denary, hexadecimal, sign and magnitude, two’s complement, binary addition, binary subtraction, normalisation of floating point numbers, floating point arithmetc, bitwise manipulation, masks (AND, OR, XOR) and character sets (ASCII, Unicode). Based on the OCR H446 Computer Science A-Level specification. Exam Board: OCR A-Level 4.1 - Data Types Specification: Computer Science H446 Watch on YouTube : Data types Denary & binary Sign and magntiude Two's complement Binary addition Binary subtraction Hexadecimal & binary Hexadecimal & denary Floating point Floating point normalisation Floating point addition Floating point subtraction Binary shifts Masks (AND, OR, XOR) Character sets This is a mathematical topic that requires conversion between the binary , denary (decimal ) and hexadecimal number systems . Representing positive and negative binary values is included, as well as adding and subtracting binary numbers and using normalised floating point to represent decimal numbers . Data Types Data types are needed so that the computer knows how to store , process and interpret data correctly . They help ensure that only valid operations are performed on data . For example, you can add two numbers , but not a number and a word . Common data types: Integer : A whole number , e.g. 7 or -12 . Real : A decimal number , e.g. 3.14 or -0.5 . Boolean : A data type with only two possible values - True or False . Character : A single letter , digit or symbol , e.g. ‘k ’, ‘7 ’, or ‘? ’. String : A sequence of characters treated as text, e.g. “CSNewbs ”. Converting from one data type to another is called casting , e.g. age = str(age) would convert the variable age to a string in Python . YouTube video uploading soon Binary Binary is a base-2 number system with all values comprised only of 0 and 1 , e.g. 01011001 . Denary (also called decimal ) is the base-10 number system you grew up learning, with 10 possible values between 0 and 9 , e.g. 453 . Computers use binary because they are built from electronic components (transistors ) that have two states (on and off ), which are easily represented by 1s and 0s . All data processed and stored by the computer (e.g. numbers , text , images and sounds ) are represented in binary . To convert an 8-bit binary value to denary , write 128 - 64 - 32 - 16 - 8 - 4 - 2 - 1 above the binary and add together the values with a 1 underneath . For example, 10101101 is 173 (128 + 32 + 8 + 4 + 1 ). YouTube video uploading soon Storing Negative Numbers -183 Sign and Magnitude and Two’s Complement are two methods of representing negative numbers in binary . In Sign and Magnitude , the most significant bit (MSB ) represents the sign - 0 for positive and 1 for negative - while the remaining bits store the number’s magnitude (value ). For example, in 8-bit form, 0 101 0010 is +82 and 1 101 0010 is -82 . However, this method has two representations of zero (+0 and -0 ), which can cause problems and may give incorrect results if used to add or subtract . In Two’s Complement , negative numbers are represented by inverting all bits of the positive value and adding 1 to the result. This method has only one zero and makes binary addition and subtraction simpler . YouTube video uploading soon YouTube video uploading soon Binary Addition & Subtraction Binary addition works from right to left but only uses the digits 0 and 1 . The key rules are: 0 + 0 = 0 0 + 1 = 1 1 + 0 = 1 1 + 1 = 10 (write down 0 and carry 1 to the next left column ). 1 + 1 = 1 = 11 (write down 1 and carry 1 to the next left column ). If the final addition produces an extra carry bit , it may indicate an overflow error , if the result is too large to fit in the available bits . Binary subtraction can be done using borrowing , similar to denary subtraction , or more commonly by using two’s complement . In two’s complement subtraction , you add the negative version of one number (found by inverting the bits and adding 1 ) to the other to perform subtraction using binary addition rules . YouTube video uploading soon YouTube video uploading soon Hexadecimal 9E8A Hexadecimal is a base-16 number system using the digits 0 to 9 and the letters A to F, where A = 10 and F = 15 in denary . It’s often used in computing because it provides a shorter , more readable way to represent long binary values . For example, two hex digits represent eight binary bits , making conversions quick and efficient . To convert from binary to hexadecimal , split the binary number into groups of four bits (from right to left ) and convert each group into its hex equivalent . Example: 1101 0110 → 1101 (14 → D ) and 0110 (6 ) → D6 . To convert hexadecimal to binary , replace each hex digit with its 4-bit binary equivalent . Example: 2F → 0010 (2 ) and 1111 (15 → F ) → 0010 1111 . The easiest method to convert between denary and hexadecimal is to convert the value to binary first . Example: 26 → 0001 1010 → 1A . YouTube video uploading soon YouTube video uploading soon Floating Point Floating point is a way of representing real (decimal ) numbers in binary using a mantissa and an exponent . It allows computers to store a wide range of values efficiently , including very small and very large numbers . Floating point normalisation means adjusting the number so that the mantissa begins with a 01 (if it is positive ) or 10 (if it is negative ). This ensures the representation is unique and uses all available bits in the mantissa for precision . To add or subtract floating point numbers , the exponents must first be made equal by shifting the mantissa of the smaller number . Once aligned , the mantissas are added or subtracted , and the result is then normalised again to maintain the correct form . YouTube video uploading soon YouTube video uploading soon Binary Shifts A binary shift moves all the bits in a binary number left or right by a set number of places . A left shift moves all bits to the left , filling the empty right-hand bits with zeros . Each left shift multiplies the number by 2 . For example, shifting 0001 0100 (20 ) one place left gives 0010 1000 (40 ). A right shift moves all bits to the right , discarding the rightmost bits . Each right shift divides the number by 2 . For example, shifting 0010 1000 (40 ) two places right gives 0000 1010 (10 ). YouTube video uploading soon Masks A mask is a binary pattern used with bitwise operations (such as AND , OR and XOR ) to manipulate specific bits within a binary value . An AND mask is used to clear (set to 0 ) specific bits . Any bit ANDed with 0 becomes 0 , and any bit ANDed with 1 stays the same . For example, 1011 0110 AND 0000 1111 = 0000 0110 - the mask keeps only the lower four bits . An OR mask is used to set (turn on ) specific bits . Any bit ORed with 1 becomes 1 , and with 0 stays the same . For example, 1010 0000 OR 0000 1111 = 1010 1111 . An XOR mask is used to toggle (invert ) specific bits . Any bit XORed with 1 flips (0 → 1 or 1 → 0 ), while XORed with 0 stays the same . For example, 1010 1010 XOR 0000 1111 = 1010 0101 . YouTube video uploading soon Character Sets A character set is a collection of characters (letters , numbers , symbols and control codes ) that a computer can recognise , store and process . Each character is represented by a unique binary code . ASCII (American Standard Code for Information Interchange ) is an early character set that uses 7 bits to represent 128 characters , including English letters , digits , punctuation and control characters . It’s simple and compact but limited to English and basic symbols . Extended ASCII uses 8 bits for 256 characters . Unicode was developed to overcome ASCII’s limitations by representing characters from all languages and writing systems . It uses up to 32 bits and includes over 140,000 characters , allowing consistent representation of text across different devices and platforms . YouTube video uploading soon This page is under active development. Check here for the latest progress update. Q uesto's K ey T erms Data Types: integer, real, Boolean, character, string Number Systems: binary, denary (decimal), hexadecimal, sign and magnitude, two's complement, binary addition, binary subtraction, floating point, floating point normalisation, floating point addition, floating point subtraction Binary shifts: left shift, right shift Masks: mask, bitwise operator, AND, OR, XOR Character Sets: character set, ASCII, Unicode D id Y ou K now? Gottfried Wilhelm Leibniz , a German mathematician , is credited with inventing the binary number system in the 17th century , hundreds of years before computers existed. Leibniz biscuits are named after him. 3.4 - Web Technologies A-Level Topics 4.2 - Data Structures

Learn about the different skills and attributes that are required for IT roles including a network manager, programmer, animator and technician. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification. 4.5 - Job Roles Exam Board: OCR Specification: 2016 - Unit 1 There are several different IT-related roles within most companies. Each role requires specific skills and attributes to be performed successfully. Try to apply the most suitable personal attributes that were described in 4.3 , as well as any other important skills relevant to the role , such as programming. Self-motivation Leadership Respect Dependability Punctuality Problem Solving Determination Independence Time Management Team Working Numerical Skills Verbal Skills Planning & Organisation Network Manager A network manager must control a group of employees with strong leadership to clearly set out their vision for the team. They must be able to motivate and encourage the team members to meet objectives . Because a network manager is high-ranking, there may not be many senior staff above them so they must be self-motivated and able to complete tasks independently , without being monitored . Network managers must be dependable and decisive , able to weigh up the consequences of a decision and make tough calls whilst under pressure . Time management is an important attribute for a network manager, they must be able to prioritise tasks and ensure deadlines are kept to . IT Technician IT technicians must have good interpersonal skills so that they can communicate clearly with other employees or customers. They should be able to use simplified terminology to help another person with their problem. They must be able to use questioning effectively to work out what the issue is to begin to solve it. IT technicians should have plenty of experience with hardware and software troubleshooting and be able to use a range of troubleshooting tools to solve a problem. They need to be respectful to customers and employees when solving a problem and show determination , as well as self-motivation , to fix issues within acceptable time limits . Programmer A programmer needs to be competent in specific programming languages that the company use. It would be beneficial to have knowledge of more than one programming language so they can be more versatile and approach a problem in different ways . Programmers need to have a logical mind so that they are able to creatively solve problems. Using computational thinking is an important set of skills that programmers should have - for example, by using decomposition to break a large problem into smaller, more manageable chunks. They must have good planning and organisational skills so that they can stay on top of the numerous tasks that need to be done. They need good time management skills to prioritise the more important tasks and stick to a deadline . Programmers must be patient individuals, all programs will contain errors that must be debugged and rewritten numerous times. Good interpersonal skills are necessary so programmers can work efficiently in teams - often multiple programmers will work on subsections of the same program that fit together later. Web Designer & Animator Web designers create , plan and code web pages to fit specific requirements made by their customers. They must create both the technical and graphical aspects of the web page, editing both how it looks and how it works. Web designers could also be responsible for maintaining a site that currently exists. They would need to have sufficient knowledge of using HTML (HyperText Markup Language ) for the structure and content of the webpage and CSS (Cascading Style Sheets ) for the formatting and style . An animator may use a mixture of digital and hand-drawn images or even puppets and models. The main skill of animation is still artistic ability , but there is an ever-increasing need for animators to be experienced with technical computer software . Animators usually work as part of a team with strict deadlines . Q uesto's Q uestions 4.5 - Job Roles: 1. Describe the key skills and personal attributes that a new programmer should have. [10 ] 2. A brief job description of a web designer and an animator are shown above on this page. Use the descriptions of what makes a suitable network manager, IT technician and programmer to help you explain which personal attributes and skills are required for: a) A web designer b) An animator [8 each ] 4.4 - Ready for Work Topic List 4.6 & 4.7 - Bodies & Certification