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Learn about lossy and lossless compression and the lossless compression algorithms run-length encoding and dictionary coding. This topic also covers symmetric and asymmetric encryption and the uses of hashing. Based on the OCR H446 Computer Science A-Level specification. Exam Board: OCR A-Level 3.1 - Compression, Encryption and Hashing Specification: Computer Science H446 Watch on YouTube : Lossy & Lossless Compression Lossless Compression Algorithms Encryption Hashing Lossy vs Lossless Compression Compression is the process of reducing the size of a file so it takes up less storage space and can be transmitted more quickly over a network . It works by encoding data more efficiently or removing unnecessary information . The main benefits of compression include faster file transfer speeds , reduced storage requirements and improved performance when streaming data . Lossy compression permanently removes some data that is less important to human perception , such as subtle sounds or image details , resulting in smaller file sizes but slightly lower quality . Lossless compression reduces file size without losing any data , allowing the original file to be perfectly restored after it is decompressed . YouTube video uploading soon Lossless Compression Algorithms There are two types of lossless compression that you need to know: Run-Length Encoding (RLE ) is a simple form of lossless compression that reduces file size by storing repeating data as a single value and a count . For example, a sequence like AAAAABBBCCCC could be stored as A5B3C4 , saving space in files with many repeated elements , such as pixels in images . Dictionary Encoding replaces repeating patterns of data with shorter codes that reference entries in a dictionary . The dictionary stores common sequences once , and each repetition is replaced by a shorter reference , making it efficient for text and other data with recurring patterns . YouTube video uploading soon Encryption Encryption is the process of converting readable data (plaintext ) into an unreadable form (ciphertext ) to prevent unauthorised access . It ensures the confidentiality and security of information during storage or transmission . There are two key types of encryption : Symmetric encryption uses the same key for both encryption and decryption , meaning the sender and receiver must share the key securely . It is fast and efficient , making it suitable for encrypting large amounts of data . However, key distribution is a major risk if the key is intercepted . Asymmetric encryption uses a pair of keys - a public key for encryption and a private key for decryption . It is more secure for communication but slower due to complex mathematical processes . Asymmetric encryption is often used to exchange symmetric keys securely before data transfer . YouTube video uploading soon Hashing Hashing is the process of applying a mathematical function (hash function ) to data to produce a fixed-size value , known as a hash . It is a one-way process , meaning the original data cannot be reconstructed from the hash . Hashing is commonly used for data integrity checks , password storage and digital signatures . Even a tiny change in the input data produces a completely different hash , making it useful for detecting tampering or corruption . YouTube video uploading soon This page is under active development. Check here for the latest progress update. Q uesto's K ey T erms Compression: lossy compression, lossless compression, run-length encoding, dictionary encoding Encryption: plaintext, ciphertext, key, symmetric encryption, asymmetric encryption Hashing: hash function, hash D id Y ou K now? 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 . 2.4 - Programming Languages A-Level Topics 3.2 - Databases

Learn about algorithms including pseudocode and flowcharts. Based on the 2020 Eduqas (WJEC) GCSE specification. 8.2: Understanding Algorithms Exam Board: Eduqas / WJEC Specification: 2020 + What is an algorithm? An algorithm is a set of instructions , presented in a logical sequence . In an exam you may be asked to read and understand an algorithm that has been written. To prove your understanding you may be asked to respond by actions such as listing the outputs of the algorithm, correcting errors or identifying an error within it. Programmers create algorithm designs as a method of planning a program before writing any code. This helps them to consider the potential problems of the program and makes it easier to start creating source code. There are two main methods of defining algorithms : Defining Algorithms - Pseudocode & Flowcharts Pseudocode Pseudocode is not a specific programming language but a more general method of describing instructions . It should be unambiguous, and it should not resemble any particular kind of programming language (e.g. Python or Java), so it can theoretically be turned into working code in any language. Generally, pseudocode can be written in any way that is readable and clearly shows its purpose. However, the Eduqas exam board advises that pseudocode for the programming exam should follow the conventions below : Annotation { Write your comment in curly brackets} Define data type price is integer firstname is string Declare a variable's value set price = 100 set firstname = "Marcella" Input / output output "Please enter your first name" input firstname Selection (must have indentation) if firstname = "Steven" then output "Hello" + firstname elif firstname = "Steve" then output "Please use full name" else output "Who are you?" end if Iteration (while loop) while firstname ! = "Steven" output "Guess my name." input firstname repeat Iteration (for loop) for i in range 10 input item next i Define a subroutine Declare Sub1 [Subroutine content indented] End Sub1 Call a subroutine call Sub1 Flowcharts A flowchart can be used to visually represent an algorithm. The flowchart symbols are: Algorithm Examples Below are two different methods for representing the same algorithm - a program to encourage people to buy items cheaply at a supermarket. The program allows the price of items in a supermarket to be entered until the total reaches 100. The total price and the number of items entered are tracked as the program loops. Once the total reaches 100 or more, an if statement checks how many items have been entered and a different message is printed if there are 20 or more items, 30 or more items or less than 20 items. Pseudocode Flowchart {This is a program to see how many items you can buy in a supermarket before you spend over £100} total is integer, itemsentered is integer, itemprice is integer set total = 0 set itemsentered = 0 while total < 100 output "enter the price of the next item" input itemprice total = total + itemprice itemsentered = itemsentered + 1 repeat if itemsentered >= 20 then output "You are on your way to saving money." elif itemsentered => 30 then output "You're a real money saver." else output "Look for better deals next time." end if Reading Algorithms In an exam you may be asked to read an algorithm and prove your understanding , most commonly by listing the outputs . Start from the first line and follow the program line by line , recording the value of variables as you go . When you encounter a for loop , repeat the indented code as many times as stated in the range . Example Algorithm: Start NewProgram i is integer maxvalue is integer input maxvalue for i = 1 to maxvalue output (i * i) ??????? output 'program finished' End NewProgram Example Questions: 1. List the outputs produced by the algorithm if the 'maxvalue' input is 5 . 2. State the code that has been replaced by '???????' and what the code's purpose is. Example Answers: 1. Outputs: 1 4 9 16 25 program finished 2. Missing Code: next i Purpose: Moves the loop to the next iteration. Watch on YouTube Q uesto's Q uestions 8.2 - Understanding Algorithms: 1a. Read the algorithm shown on the left and list all outputs in the correct order if the inputs are 2 for height and 72 for weight . 1b. Give the code that is missing from line 25 . 8.1 - Programming Principles Theory Topics 8.3 - Writing Algorithms

The most common errors made in Grennfoot when making a game and how to fix them, including when missing punctuation is expected or the end of file is reached while parsing. Common Greenfoot Errors Greenfoot Home If the world becomes greyed out and you can't click on anything then an error has occurred. The actor with the error will have red lines on it. When an error occurs, a red squiggly line will appear underneath the problem. Hover your mouse over the line and a helpful message will appear to help you solve the issue. Some of the more common errors (and how to fix them) are listed below: ; expected Every line with a white background must end in a semi colon ( ; ) ) expected You have missed a bracket . Count the number of open brackets and the number of closed brackets on a line and make sure you have an equal number of both. reached end of file while parsing You are missing at least one curly bracket ( } ) at the end of your program . Press enter to move onto a new line at the bottom; you must have a closed curly bracket with a yellow background and another closed curly bracket with a green background . cannot find symbol You have typed a command incorrectly . Greenfoot uses a system where commands have no spaces and each word after the first word is uppercase . Such as isKeyDown not IsKeyDown and not isKeydown. Check your spelling and capitals carefully. Stuck ? If you start typing but can't remember what commands come next, press Ctrl and Space together to show a list of all possible commands that you can use.

Learn how to use variables in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. top Python 1d - Using Variables Printing Variables Within Sentences Join sentences and variables together using a plus symbol (+ ). Joining strings together like this is called concatenation . name = "Marina" print( "Hello " + name + ", nice to meet you." ) = Hello Marina, nice to meet you. Remember to use speech marks for your printed statements but no speech marks for variable names . You need to use the + symbol before and after each variable. direction = "north" country = "Wales" print ( "Have you been to the " + direction + " of " + country + "?" ) = Have you been to the north of Wales? Commas can be used an alternative to the + symbol but they will automatically add a space . day = "Saturday" print ( "My birthday is on a" + day + "this year." ) print ( "My birthday is on a" , day , "this year." ) = My birthday is on aSaturdaythis year. My birthday is on a Saturday this year. Using Variables Task 1 ( Pizza Toppings) Use a variable named topping1 and another named topping2. Print a sentence that uses both variables names. Example solution: My favourite pizza is ham and mushroom. Printing Number Variables Within Sentences To join strings and number values then you must use a comma as a plus will not work: cookies = 4 print ( "Munch! There's only" , cookies , "left." ) = Munch! There's only 4 cookies left. You need to use a comma before and after each variable. Using Variables Task 2 ( Stars ) Make a variable named stars and set it to a large number. Print a sentence with the stars variable. Example solution: I think there are 827392012 stars in the sky! Using Variables Task 3 ( Age & Month) Use a variable named age and set it to your current age. Make a variable named month and set it to the month you were born. Remember to use speech marks for text , e.g. month = "August" but no speech marks for numbers (your age). Print a sentence that uses both variables names . Example solution: I am 14 and I was born in August. Using f-Strings Another method of using variables within a printed sentence is to use f-strings . Type the letter f before your output and place your variable names in curly brackets - { } Variables of any data type can be used with f-strings. name = "Tony Stark" alias = "Iron Man" print( f"Did you know {name} is actually {alias} ?" ) = Did you know Tony Stark is actually Iron Man? Using Variables Task 4 ( F-Strings) Create and give a value to three variables : movie_name actor year Use an f-string to print a sentence that uses all three variables. Example solution: Did you know that Harry Potter and the Order of the Phoenix stars Daniel Radcliffe and was released in 2007? ⬅ 1c - Creating Variables Sec tion 1 Practice Tasks ➡

Learn about six network devices - hub, switch, router, bridge, WAP and NIC. Also, learn about routing tables and cost diagrams. Based on the 2020 Eduqas (WJEC) GCSE specification. 3.4: Network Hardware & Routing Exam Board: Eduqas / WJEC Specification: 2020 + Network Devices Hub A hub receives data packets from a connected device and transfers a copy to all connected nodes . Switch A switch receives data packets , processes them and transfers them on to the device specifically listed in the destination address of the packet. Router Routers are used to transfer data packets between networks . Data is sent from network to network on the internet towards the destination address listed in the data packet. A router stores the address of each computer on the network and uses routing tables to calculate the quickest and shortest path . Bridge A bridge joins together two networks that use the same base protocols . For example, a bridge could link together a LAN to another LAN . Wireless Access Point (WAP) Provides a link between wireless and wired networks . It creates a wireless local area network that allows WiFi enabled devices to connect to a wired network. Network Interface Card (NIC) A Network Interface Card (often shortened to NIC ) is an internal piece of hardware that is required for the computer to connect to a network . It used to be a separate expansion card but now it is commonly built directly into the motherboard (and sometimes known as a network adapter ). Wireless network interface cards ( WNIC ) permit a wireless network connection. Routing A routing table is a list of the optimal routes for data packets to be sent from one device to another. Routing tables should be kept accurate and up to date to ensure that packets are transferred as quickly as possible . During routing the lowest cost route is calculated . This is the shortest path with the fastest nodes to transfer data. Below is a simplified network and basic routing table showing the lowest cost (optimal) route using node A as the source address. Q uesto's Q uestions 3.4 - Network Hardware & Routing: 1a. Describe the difference between a hub and a switch . [ 2 ] 1b. Explain how a modem works. [ 2 ] 1c. Describe the purpose of a router . [ 2 ] 1d. Describe the difference between a gateway and a bridge . [ 2 ] 1e. State what WAP stands for and describe its purpose . [ 2 ] 1f. State what NIC stands for and why it is required . [ 2 ] 2a. Describe what a routing table is and why they should be maintained . [ 2 ] 2b. In terms of routing, what does a low-cost route mean? [ 2 ] 2c. Copy and complete the routing table below using node J as the source address . [ 4 ] 3.3 - Network Topology Theory Topics 3.5 - Protocols

Test your understanding of data types, calculations and modulo. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. top Python - Section 3 Practice Tasks Task One: Square Number Create a program that asks the user to input a number and then prints the square of that number - to do this, multiply the number by itself . Remember: Break up variables and parts of a sentence in a print line by using commas. Example solutions: Enter a number: 12 The square of 12 is 144 Enter a number: 7 The square of 7 is 49 Task Two: Multiplying Numbers X Example solutions: Create a program that asks the user to input two numbers (num1 and num2 ). Multiply the two numbers together and print the total . Remember: Break up integer variables in a print line by using commas between each part of the sentence. Enter number one: 7 Enter number two: 9 7 x 9 = 63 Enter number one: 8 Enter number two: 12 8 x 12 = 96 Task Three: Turning 65 Example solutions: Create a program to input how old the user will turn this year and then print the year they will turn 65 . You could do this in just two lines but before trying that work out on paper the steps to calculating your own age you will turn 65. What steps did you take? Try to recreate those steps in Python. You might need to create another variable to make it easier. How old will you turn this year? 15 You will turn 65 in 2073 How old will you turn this year? 42 You will turn 65 in 2046 Task Four: Multiplication Table Let the user enter a number then print the first five multiplications in its times table. This can be done more simply when you learn about for loops but for now you will need to multiply the number by 1 , then multiply it by 2 etc. Try to make this program better by displaying the number and the value it is multiplied by in your print statements. Simple example solution: Enter a number: 8 8 16 24 32 40 Better example solution: Enter a number: 7 7 x 1 = 7 7 x 2 = 14 7 x 3 = 21 7 x 4 = 28 7 x 5 = 35 ⬅ 3b - Simple Calculations 4a - If Statements ➡

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