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Learn about the different types of applications software including productivity programs, business tools and IDEs. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification. 2.2: Applications Software Exam Board: OCR Specification: 2016 - Unit 1 What is applications software? Don't confuse applications software and apps . Apps generally have a single purpose , such as a game like Angry Birds or the torch tool on a phone. Applications software can be used for a number of different functions depending on the user's needs and their purpose. Productivity Software This is general use software for completing a range of tasks accurately and efficiently . Key examples include word processors (e.g. Microsoft Word or Google Docs), presentation software (e.g. Microsoft PowerPoint or Google Slides) and web browsers (e.g. Microsoft Edge or Google Chrome). Email applications (e.g. Microsoft Outlook or Gmail) are beneficial to organisations because staff can send information to many customers at once which is a simpler and less costly method of communication than something like sending letters or leaflets in the mail. Emails can also include attachments of important documents and include multimedia elements like images and videos to make communication more interesting . Databases and Spreadsheets Database tables and spreadsheets can store both numerical and textual data ready for analysis . Examples include simple database tables and financial spreadsheets of a company's profits each year. Microsoft Access is an example of database software that uses tables of records and Microsoft Excel is an example of spreadsheet software . Data can be sorted numerically or alphabetically for both software types but graphs can be created from spreadsheets to visualise data . When using spreadsheets (or databases) records can be locked ('record locking' ) so that only one person can make edits to a specific record at any one time. Edits will be saved before unlocking the file. This will stop data being incorrectly overwritten and will ensure that the data in the spreadsheet is up-to-date, accurate and fit for purpose. Development Tools These are tools for programmers who are creating or modifying software . An integrated development environment ( IDE ) is software used to create , edit and debug (fix) programs . An IDE features a number of tools , including: A source code editor to type program code into. It may contain features such as error highlighting and automatic formatting . Because IDEs use high-level languages like Python or Java , a translator is required to convert the source code into machine code ( binary ) so that it can be understood and processed by the CPU . A compiler is a type of translator that converts instructions into machine code (binary) in one go . An interpreter is a type of translator that converts instructions into machine code (binary) line by line . A debugger is used to test code and display errors . Other development tools aid programmers with developing and maintaining websites and apps for phones / tablets. An advantage of databases over spreadsheets is that data can be atomised - meaning it can be stored in separate tables (e.g. one for patients and one for doctors ) with records linked through relationships . This minimises data redundancy (duplication ), meaning there is a lower chance of making errors , and it is easier to search through the table as each record will only appear once . A search through a database is called a 'query '. Business Software This is specialist software for businesses , often made bespoke for an organisation based on their needs . Types of business software: Project management software allows teams of workers to collaborate and split large projects into manageable tasks with clear deadlines and assigned roles . A management information system (MIS ) processes a large amount of data and organises it for use in decision-making and general data analysis . See more about an MIS in section 3.5 . Multimedia programs such as video editors or animation suites can be used to create high-quality videos with images , audio and video clips . Collaboration tools for businesses allow employees to share ideas and resources in real-time . Publishing software allows users to implement text and images into eye-catching designs such as posters , leaflets or static adverts to include on a website. Expert systems use large databases for automatic decision-making , often making use of AI to quickly solve complex problems . A healthcare example of an expert system is a medical diagnosis program that may suggest possible illnesses when a patient's symptoms are input . CAD / CAM One example of business software used for the design and manufacture of a product is CAD / CAM (C omputer-A ided D esign / C omputer-A ided M anufacturing). CAD is used to create highly detailed digital designs and CAM translates these designs into instructions for manufacturing machines to make the product physically. These software packages use 3D modelling and image rendering along with exact measurements to create precise designs ready to be manufactured . Engineers use them to design and make mechanical parts and architects use them to create detailed building models and blueprints . Q uesto's Q uestions 2.2 - Applications Software: 1. State four different kinds of productivity software and briefly describe how each could be used . For example: "Word processors can be used to type up a letter in an office or write an essay for school." [8 ] 2. Describe two differences between database and spreadsheet software. [2 ] 3a. What is an Integrated Development Environment ? [1 ] 3b. Describe three tools used in an IDE. [6 ] 4. Giving brief examples of how they can be used, state four different types of business software . [8 ] 5. Suggest how a website design company could use each of the three types of applications software (Productivity Software , Development Tools and Business Software ). [ 6 ] 2.1 - Types of Software Topic List 2.3 - Utility Software

Navigate between all topics in the OCR A-Level Computer Science H446 specification. Includes all topics from Component 1 (Computer Systems) and Component 2 (Algorithms and Programming). OCR Computer Science A-Level These pages are based on content from the OCR H446 Computer Science specification . This website is in no way affiliated with OCR . Component 1: Computer Systems Paper 1 Playlist on YouTube This content is under active development. Check here for the latest progress update. OCR A-Level Key Term Generator 1. Hardware 1.1 - Structure & Function of the Processor (The CPU) 1.2 - Types of Processor 1.3 - Input, Output & Storage 2. Software 2.1 - Systems Software 2.2 - Applications Generation 2.3 - Software Development 2.4 - Types of Programming Language 3. Networks & Databases 3.1 - Compression, Encryption & Hashing 3.2 - Databases 3.3 - Networks 3.4 - Web Technologies 4. Data & Logic 4.1 - Data Types 4.2 - Data Structures 4.3 - Boolean Algebra 5. Laws 5.1 - Computing-Related Legislation 5.2 - Moral & Ethical Issues Component 2: Algorithms & Programming 1. Computational Thinking 1.1 - 1.5 - Computational Thinking 2. Problem Solving & Programming 2.1 - Programming Techniques 2.2 - Computational Methods 3. Algorithms 3.1a - 3.1d - Algorithm Complexity 3.1e - Data Structure Algorithms 3.1f - Standard Algorithms

Learn about the different protocols used on networks - HTTP, HTTPS, TCP, IP, FTP and SMTP. Also learn about protcol layers in the 4-layer TCP/IP model. Based on the J277 OCR GCSE Computer Science specification (first taught from 2020 onwards). 3.2b: Protocols & Layers Exam Board: OCR Specification: J277 Watch on YouTube : IP & MAC Addresses Protocols & Standards Common Protocols Protocol Layers Protocols A protocol is a set of rules that allow devices on a network to communicate with each other . TCP / IP (Transmission Control Protocol / Internet Protocol) TCP / IP is actually two separate protocols that combine together. TCP is a protocol that allows packets to be sent and received between computer systems. It breaks the data into packets and reorders them back into the original data at the destination. IP is a protocol in charge of routing and addressing data packets . This ensures data packets are sent across networks to the correct destination . It is also an addressing system - every device on a network is given a unique IP address so data packets can be sent to the correct computer system. HTTP is used to transfer web pages over the Internet so that users can view them in a web browser . All URLs start with either HTTP or HTTPS (e.g. https://www.csnewbs.com). HTTPS is a more secure version of HTTP that works with another protocol called SSL ( Secure Sockets Layer ) to transfer encrypted data . You should see a padlock symbol in the URL bar if your connection to that website is secure. HTTP/HTTPS (Hypertext Transfer Protocol) Transfer Protocols FTP ( File Transfer Protocol ) is used to transfer files across a network. It is commonly used to upload or download files to/from a web server . SMTP ( Simple Mail Transfer Protocol ) is a protocol used to send emails to a mail server and between mail servers . POP ( Post Office Protocol ) and IMAP (Internet Message Access Protocol ) are both protocols for receiving and storing emails from a mail server. POP will delete an email from the email server once it has been downloaded to a device . Pop! IMAP syncs the message with an email server so it can be accessed by different devices . IP Address & MAC Address There are two versions of IP addressing currently used - IPv4 and IPv6 . IPv4 is a 32-bit address , represented in denary , that allows for over 4 billion unique addresses . It has four 8-bit segments of denary values (from 0 to 255) separated by full stops . IPv4 example: 145.13.218.102 IPv6 is a 128-bit address , represented in hexadecimal , that allows for an undecillion unique addresses . It has eight 16-bit segments of four hexadecimal values (0000 - FFFF), separated by colons . IPv6 example: 736E:1029:A4B3:902D:77B2:72FF:AE62:0912 A MAC address is a unique hexadecimal number assigned to each network interface card/controller inside a networked device such as a router or laptop . A MAC address is a 48-bit address made up of six 8-bit pairs in hexadecimal , separated by dashes . While an IP address may change , the MAC address can’t be changed . MAC stands for Media Access Control . Network Interface Card (NIC) MAC example: 19-C2-D1-47-AA-38 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 by interpreting signals in the same way , regardless of the manufacturer . TCP/IP Stack & Layers What is TCP/IP? TCP/IP (Transmission Control Protocol / Internet Protocol ) is a set of protocols that operate on different layers . These two protocols are used together to allow computers to communicate on a network . What is a protocol layer? A layer is a division of network functionality - each layer provides a specific function to assist the transmission of the data that is being sent. TCP/IP is split into four layers (named Application , Transport , Internet and Link ). Important Note: You do not need to know any layer names or the purpose of any specific layers in the OCR GCSE J277 specification , just what layers are and why they’re used . Why are protocol layers used? Layers are self-contained , so they allow different developers to concentrate on one aspect of the network at a time . A layer can be taken out and edited without affecting other layers . Protocol layers are used to visualise the different parts of a network , as each of the four layers of TCP/IP has a specific role and is associated with different protocols . Protocols are broken down into well-defined , specific layers to simplify design , making it easier to identify errors (known as troubleshooting ). Each layer uses specific protocols , so layering ensures these protocols are applied in a specific order . This process uses abstraction and layers only communicate with adjacent layers for easy compatibility . Q uesto's Q uestions 3.2b - Protocols & Layers: 1. Describe each of the following protocols . It might be helpful to also draw an icon or small diagram for each one: a. TCP [ 2 ] b. IP [ 2 ] c. HTTP & HTTPS [ 3 ] d. FTP [ 2 ] e. SMTP [ 2 ] f. POP3 & IMAP [ 2 ] 2. State which protocol would be used in the following scenarios : a. Transferring a music file to a friend over the internet. [ 1 ] b. Sending an email to a family member in America. [ 1 ] c. Using a webpage to enter a password securely. [ 1 ] d. Receiving an email from a bank. [ 1 ] 3a. What are networking standards ? [ 2 ] 3b. What is TCP/IP ? [ 2 ] 3c. What is a protocol layer ? [ 2 ] 3d. Give at least two reasons why protocols are split into layers . [ 4 ] 3.2a - Wired & Wireless Networks Theory Topics 4.1 - Security Threats

Learn about key computing laws including the Data Protection Act (2018), Computer Misuse Act (1990), Copyright, Designs and Patents Act (1988) and software licences. Based on the J277 OCR GCSE Computer Science specification (first taught from 2020 onwards). Exam Board: OCR 6.1b: Legislation Specification: J277 Watch on YouTube : Data Protection Act Computer Misuse Act Copyright, Designs & Patents Act Open Source Licence Proprietary Licence Data Protection Act (2018) 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 state that data must be: 1. Collected lawfully and processed fairly. 4. Data must be accurate and up-to-date. 2. Only used for the reasons specified. Principles of the Data Protection Act (2018) 5. Data must not be stored for longer than necessary, 3. Data must be relevant and not excessive. 6. Data must be stored and processed securely. 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. 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 . However, it is difficult to trace who has stolen work once it has been uploaded to the internet and copies can easily spread, especially television shows and movies. 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. Software Licences A software licence refers to how a user can legally use the software , there are two main types: Open Source Licence Source code is the software code written by programmers . If the software is open source it means that users can view and modify the source code . Linux, Python and Firefox are examples of open source software. Benefits Drawbacks Because the source code is available to edit , it can be customised to the organisation's needs . Often shared in the public domain so users can work together to modify, debug and improve a product. Unwanted features can be removed to make the software run faster . There are security risks - some editors may add malicious code to the program. Open source software is often low in price and sometimes free. It may be difficult to receive support as development is often distributed between people in different locations. The code may be prone to errors as it may not have been tested fully. It requires technical skills to be able to adapt source code efficiently and to maintain the code . Proprietary Licence Another term for a proprietary licence is closed source because the code is restricted - users are prevented from being able to view or modify the source code . You buy the right to use the software but you don't actually own it. Microsoft Office, Fortnite and Spotify are examples of closed source software. Benefits Drawbacks The code is well tested and has been professionally developed. Updates will generally be secure . Users must rely on the company to provide updates and fix issues. This might be infrequent or stop completely. The company can be held to account if it does not perform as listed in the terms and conditions upon purchase. Often not free and may be expensive. Most developers will provide some form of help/support . Users cannot modify, debug or improve the code for their own benefit. Q uesto's Q uestions 6.1b - Legislation: 1a. State the 6 principles of the Data Protection Act (2018) . [ 6 ] 1b. Explain how the Data Protection Act works . In your answer, you should include definitions of a data subject , the data controller and the Data Commissioner . [ 6 ] 2. Describe the 3 principles of the Computer Misuse Act (1990) . [3 ] 3a. What is the purpose of the Copyright, Designs & Patents Act (1988) ? [ 2 ] 3b. Describe 3 actions that CDPA (1988) prohibits . [ 3 ] 4a. Describe the difference between an open source and a proprietary licence . [ 2 ] 4b. State two benefits and two drawbacks of using software with a: Open source licence [ 4 ] Proprietary licence [ 4 ] 6.1a - Impacts of Technology Theory Topics

Learn about data structures including arrays, records, lists, tuples, linked-lists, graphs, stacks, queues, trees, binary search trees and hash tables. Based on the OCR H446 Computer Science A-Level specification. Exam Board: OCR A-Level 4.2 - Data Structures Specification: Computer Science H446 Watch on YouTube : Arrays Records Lists & tuples Stacks Queues Linked lists Trees Graphs Hash tables Data structures are used to organise and store data so it can be accessed and processed efficiently , often through the use of an index or reference . They can be static , meaning their size is fixed during program execution , or dynamic , allowing them to grow or shrink as data changes . Arrays An array is a data structure that stores a collection of items of the same data type , with each item accessed using an index . A one-dimensional (1D ) array is a simple sequence of values , such as test scores for a single person : scores = [12, 15, 18, 20] . A two-dimensional (2D ) array is like a table or grid , made up of rows and columns - for example, storing a timetable or test scores for a class . A three-dimensional (3D ) array stores data in multiple layers , like a series of 2D grids . For example, test scores for a class across multiple subjects . This page is under active development. Check here for the latest progress update. YouTube video uploading soon Records A record groups together related but different types of data under one name . Each individual piece of data within a record is called a field and each field can have a different data type (e.g. string , integer , Boolean ). For example, a student record might include fields such as Name (string ), Age (integer ) and Enrolled (Boolean ). Records are often used in databases or programming to represent real-world entities where multiple attributes need to be stored together . YouTube video uploading soon Lists & Tuples A list stores an ordered collection of items , which can be changed (mutable ) after creation. Items in a list can be added , removed or modified , and they can be of different data types . For example, in Python : myList = [10, "apple", True] . A tuple is similar to a list but is immutable , meaning its contents cannot be changed once created . Tuples are often used for fixed sets of data that should not be altered , such as coordinates or dates . For example: myTuple = (3, 5, 7) . YouTube video uploading soon Stacks A stack stores data in a last in , first out (LIFO ) order, meaning the most recently added item is the first one to be removed . It works much like a stack of plates - you can only add or remove from the top . Two integral functions are push and pop . The push operation adds (or “pushes”) a new item onto the top of the stack . The pop operation removes (or “pops”) the item from the top of the stack . Stacks are commonly used in undo features , function calls and expression evaluation , where tracking the most recent item first is important . YouTube video uploading soon Queues A queue stores items in a first in , first out (FIFO ) order, meaning the first item added is the first one removed . New items are added at the rear of the queue using an enqueue operation, and items are removed from the front using a dequeue operation. Queues are often used in task scheduling , print spooling and data buffering , where operations must occur in the same order they were requested . YouTube video uploading soon Linked Lists A linked list is a dynamic data structure made up of a series of elements called nodes , where each node contains data and a pointer to the next node in the sequence . Unlike arrays, linked lists do not store elements in contiguous memory locations , making it easy to insert or delete items without having to shift other elements . The head is the first node in the list , and the last node usually points to null , indicating the end of the list . YouTube video uploading soon Trees A tree is a hierarchical data structure made up of nodes connected by branches , starting from a single root node . Each node can have child nodes , and nodes without children are called leaf nodes . Trees are useful for representing data with natural hierarchies , such as file systems or organisational charts . A binary search tree is a special type of tree where each node has at most two children - a left and a right . All values in the left subtree are smaller than the parent node , and all values in the right subtree are larger . This structure allows for efficient searching , insertion and deletion of data , often much faster than in lists or arrays . YouTube video uploading soon Graphs A graph is made up of nodes (also called vertices ) connected by edges and is used to represent relationships between items. Graphs can be directed , where edges have a specific (one-way) direction , or undirected , where connections go both ways . They can also be weighted , where edges have values such as distance or cost , or unweighted , where all connections are equal . Graphs are widely used in computing, for example, in social networks (users and friendships ), maps (locations and routes ) and network routing algorithms . YouTube video uploading soon Hash Tables A hash table stores key–value pairs and allows for very fast data access . It uses a hash function to convert a key (such as a name or ID ) into an index (hash value ), which determines where the associated data (value ) is stored in memory . When retrieving data , the same hash function is applied to the key to find the value’s location instantly , making lookups close to constant time complexity on average . If two keys produce the same hash (a collision ), techniques such as chaining or linear probing are used to handle it . Hash tables are commonly used in databases , caches and programming languages for tasks like fast searching and indexing . YouTube video uploading soon Q uesto's K ey T erms Arrays: array, 1-dimensional, 2-dimensional, 3-dimensional, static Records: record, field, data type, primary key Lists and Tuples: list, tuple, mutable, immutable, dynamic Stacks and Queues: stack, queue, last in first out (LIFO), first in first out (FIFO), push, pop, enqueue, dequeue, pointer Linked Lists: linked list, null Trees & Graphs: tree, binary tree, binary search tree, root node, branch, graph, weights, directions Hash Table: hash table, key, value, collision, linear probing, chaining D id Y ou K now? Trees are used for dialogue options in narrative video games , displaying possible paths based on the player’s previous choices . The final ' suicide mission ' of Mass Effect 2 has hundreds of possible variations depending on ship upgrades , squad member loyalty , and assigned roles during the last mission . 4.1 - Data Types A-Level Topics 4.3 - Boolean Algebra

Learn about the advantages and disadvantages of networks, the five types of network - LAN, WAN, PAN, MAN and VPN - and differences between wired and wireless networks. Based on the 2020 Eduqas (WJEC) GCSE specification. 3.1: Network Characteristics Exam Board: Eduqas Specification: 2020 What is a network? A network is more than one computer system connected together allowing for communication and sharing of resources . There are many benefits but also some drawbacks to using a network compared to having an unconnected ('standalone' ) computer: Advantages of Networks Easily share files , software and hardware between computers. Disadvantages of Networks There is an initial cost because network devices like routers are required . Larger companies will need to buy and maintain a server . Log in from any connected computer and access your data and files. A network manager / administrator might need to be employed to maintain the network . An administrator can monitor network activity and control security settings. Data from computers on the network can be automatically backed up on central storage. Security breaches are more likely and malware , such as worms, can spread quickly across the network. If the web server fails , all connected computers won't be able to access files or log on . Network Types Networks can be split into different types , usually categorised by their geographical distance apart and the area that they serve. Local Area Network A local area network (LAN ) has computer systems situated geographically close together , usually within the same building or small site , like a school or office . Wide Area Network A wide area network (WAN ) has computer systems situated geographically distant to each other, possibly across a country or even across the world . The internet is an example of a WAN that spans the globe. Personal Area Network A PAN is a personal network for an individual , such as a photographer connecting a smartphone, desktop computer and printer together. Metropolitan Area Network A MAN is larger than a LAN but smaller than a WAN and typically covers a relatively large area like a university campus, town or city . Virtual Private Network A VPN allows for a secure and encrypted connection to a public network like the internet. It is often used to protect an individual's privacy by concealing their real location. Wired & Wireless Networks Wired Connections Wireless Connections Wireless connections, such as WiFi or Bluetooth , use no cables but require a wireless network interface card (WNIC ). Wireless connections generally have a slower speed and can be affected by the computer's distance from the wireless router as well as obstacles like walls or bad weather. Wired connections use physical cables , such as copper or fibre optic wires , and require a network interface card (NIC ) to connect to a network. These wired connections use a wired connection protocol - most commonly Ethernet . Restricted Movement Faster More Secure NIC Required Freedom of Movement Slower Less Secure WNIC Required Q uesto's Q uestions 3.1 - Network Characteristics: 1. A retirement home for the elderly is considering installing a LAN , give 3 benefits and 3 drawbacks they might find of using a network . [6 ] 2a. Describe the difference between a LAN and WAN . [2 ] 2b. Give an example of how a LAN and a WAN could each be used . [ 2 ] 3 . Explain the differences between a PAN , MAN and VPN . [ 3 ] 4. For each of the scenarios below, state which network type would be most suitable : a. The IT rooms of a secondary school . [ 1 ] b. A study in a house with a desktop and printer. [ 1 ] c. Using online banking when abroad on a holiday to stay secure . [ 1 ] d. A large technology company with offices across Europe . [ 1 ] e. Council offices with several locations across Manchester . [ 1 ] 5. Briefly compare wired and wireless networks . [ 8 ] 2.2 - Boolean Algebra 3.2 - Data Packets & Switching Theory Topics

Navigate between all Unit 2 (Global Information) topics in the OCR Cambridge Technicals Level 3 IT 2016 specification. OCR Cambridge Technicals IT Level 3 Unit 2: Global Information These pages are based on content from the OCR Cambridge Technicals 2016 Level 3 IT specification . This website is in no way affiliated with OCR . This qualification stopped in July 2025. The pages on the site will remain for at least two years. LO1 (Devices & The Internet ) 1.1 - Holders of Information 1.2 - Storage Media 1.3 - Access & Storage Devices 1.4 - Internet Connections 1.5 - WWW Technologies 1.6 - Information Formats 1.7 & 1.8 - Internet Pros & Cons LO2 (Information Styles & Quality ) 2.1 - Information Styles 2.2 - Information Classification 2.3 - Quality of Information 2.4 - Information Management LO3 (Categories & Analysis ) 3.1 - Data vs. Information 3.2 & 3.3 - Information Categories 3.4 - Stages of Data Analysis 3.5 - Data Analysis Tools 3.6 - Information Systems LO4 (Legislation ) 4.1 - UK Legislation 4.2 - Global Legislation 4.3 - Green IT LO5 (Flow of Information ) 5.1 - Data Types & Sources 5.2 - Data Flow Diagrams LO6 (Security & Protection ) 6.1 - Security Principles 6.2 - Risks 6.3 - Impacts 6.4 - Protection Measures 6.5 - Physical Protection 6.6 - Logical Protection

Learn about the three main types of memory in a computer system - RAM (Random Access Memory), ROM (Read Only Memory) and Cache Memory. Memory What is memory? Memory is where a computer stores information , instructions and data so it can use them quickly when needed . There are three main types of memory : RAM Random Access Memory ROM Read Only Memory Cache Memory What is Random Access Memory? RAM is volatile (this means that when power is lost, the data is deleted ). Every program that is being run by the computer (such as Google Chrome, Spotify or Microsoft Word) is stored in RAM . RAM is made up of a large number of storage locations , and each is identified with a unique address . What is Read Only Memory? ROM is non-volatile (this means that data is saved, even when the power is off ). The start-up instructions (for when a computer is switched on ) are stored in ROM . ROM is read-only, which means that it cannot be edited or changed . What is Cache Memory? Cache memory is fast to access because it is built into the CPU (or very close to it) . Cache memory stores data that needs to be accessed very frequently . Cache memory is very expensive , so there is only a small amount in most computers. How can a computer run faster? There are many reasons why a computer may be running slowly . Here are some methods related to memory that can help speed up a system : Close unnecessary programs to free up RAM so it doesn't run out of memory space . Add more RAM so the computer can run more programs at once without slowing down . Increase the cache size so the CPU can access important data more quickly . KS3 Home Note: Only larger systems like desktop computers can have their components easily upgraded and replaced.

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 how to handle errors in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. Python 12 - Error Handling Errors When an error occurs in Python, you may see a chunk of red text like this. This is very useful when creating programs as it tells us the exact line of the error (10), and its type (NameError). However, a completed program should have code in place for when an unexpected error occurs – we call this exception handling . General Exception In this example, Python will attempt to run the code indented beneath try . If there are no errors then the code will stop just before except . If an error does occur then the Exception code will be run . If we enter a correct value then the program will execute normally: But if an error occurs (such as writing a string when an integer is expected) then the Exception code will run : You can add the else command to your code that will execute only if there are no errors : If a valid number is entered then the else code will be printed: If a code generating an error is entered then the except code will be printed: Practice Task 1 Create a program that asks the user to input their age. Don't forget to use the int command. Use try and except to print a message if a number is not inputted. Example solution: Specific Exceptions The Exception command used in the section above is for any general error that occurs. You can also use specific except commands for a variety of errors. Below is a program with two different specific exception commands for one try statement: If a Value Error occurs, such as when the wrong data type is entered , then related code will be printed: Or if the user tries to divide by zero then a Zero Division Error will be triggered which prints a relevant response: Other types of exception can be found here . Practice Task 2 Create a program that asks the user to input a number and then divides this value by 999. Create a Value Error and Zero Division Error exception and include an appropriate message in both. Example solution for Zero Division: ⬅ 11 - Graphical User Interfac e Extended Task 1 (Pork Pies) ➡

Learn about the denary, binary and hexadecimal number systems and how to convert between them. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification. 1.8 & 1.9 - Number Systems & Conversion Exam Board: OCR Specification: 2016 - Unit 1 What is binary? What is denary? Denary (also known as decimal ) is the number system that you've been using since primary school. Denary is a base 10 number system. This means that it has 10 possible values - 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9 . How to convert from binary to denary: How to convert from denary to binary: What is hexadecimal? Hexadecimal is a base 16 number system. This means that it has 16 possible values - 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E and F . Hexadecimal is used as a shorthand for binary because it uses fewer characters to write the same value . This makes hexadecimal less prone to errors when reading or writing it , compared to binary. For example, 100111101011 is 9EB. Hexadecimal only uses single-character values. Double-digit numbers are converted into letters - use the table on the right to help you understand. How to convert from binary to hexadecimal: How to convert from hexadecimal to binary: Converting from denary to hexadecimal / hexadecimal to denary To convert from denary to hexadecimal or the other way round you must convert to binary first . Denary > Binary > Hexadecimal Hexadecimal > Binary > Denary Use the videos on this page if you need help converting to or from binary. The most common number systems question in exams are from denary to hexadecimal or from hexadecimal to denary so make sure that you practice these conversions. Q uesto's Q uestions 1.8 & 1.9 - Number Systems: 1. Explain why hexadecimal numbers are used as an alternative to binary . [ 2 ] 2. Convert the following values from binary to denary : a. 00101010 b. 11011011 c. 01011101 d. 11101110 e. 01011111 [1 each ] 3. Convert the following values from denary to binary : a. 35 b. 79 c. 101 d. 203 e. 250 [1 each ] 4. Convert the following values from binary to hexadecimal : a. 11110101 b. 01100111 c. 10111010 d. 10010000 e. 11101001 [1 each ] 5. Convert the following values from hexadecimal to binary : a. C2 b. 8A c. DE d. 54 e. F7 [1 each ] 6. Convert the following values from denary to hexadecimal : a. 134 b. 201 c. 57 d. 224 e. 101 [1 each ] 7. Convert the following values from hexadecimal to denary : a. 32 b. A5 c. 88 d. C0 e. BE [1 each ] Watch on YouTube Watch on YouTube Watch on YouTube Watch on YouTube By now you should know that computer systems process data and communicate entirely in binary . Section 1.7 explained different binary storage units such as bits (a single 0 or 1), nibbles (4 bits) and bytes (8 bits). Binary is a base 2 number system. This means that it only has 2 possible values - 0 or 1 . Click the banners above to try self-marking quizzes (Google Form) on these topics. Denary to Binary: Binary to Denary: Binary to Hexadecimal: Hexadecimal to Binary: 1.7 - Units of Measurement Topic List 2.1 Software Types

Learn about operating systems, memory management (segmentation and paging), scheduling, interrupts, the BIOS, device drivers and virtual machines Based on the OCR H446 Computer Science A-Level specification. Exam Board: OCR A-Level 2.1 - Systems Software Specification: Computer Science H446 Watch on YouTube : Operating systems functions Paging & segmentation Interrupts Scheduling algorithms Types of operating system BIOS Device drivers Virtual machines This topic looks at how the operating system manages the resources of a computer system . It also includes programs related to the operating system , such as the BIOS , device drivers and virtual machines . Operating Systems The operating system performs essential functions to keep a computer running efficiently . It provides a user interface , such as a command line or graphical user interface ( GUI ), and ensures system security by managing access rights and protecting files . The OS manages hardware , coordinating devices like the CPU , printers and hard drives and provides built-in utilities for tasks such as file management and disk defragmentation . It acts as a platform for software , allowing applications to be installed and run . The OS also schedules jobs , handles interrupts from devices, and manages memory , ensuring each process has the resources it needs without conflicts. Paging & Segmentation Paging is a memory management method that splits memory into equal-sized blocks called pages . This makes memory use more efficient as programs don’t need to be stored in one continuous block but unused space may be wasted inside a page . Segmentation divides memory into segments of different sizes based on program structure . This makes it easier to organise parts of a program , but because segments are different sizes , it can leave small unused gaps in memory that can’t be easily filled by other data. Interrupts An interrupt is a signal that tells the CPU to pause its current task and respond to something more urgent . Interrupts can come from hardware , such as a keyboard press , or from software , such as an error . When an interrupt occurs , the CPU saves its current state by placing current register values into a stack . The CPU runs an interrupt service routine ( ISR ) to handle the interrupt event . After the ISR finishes , the CPU restores its state by popping values from the stack and continues the original program . Scheduling Scheduling algorithms are used by the CPU to decide the order in which processes are executed . They aim to manage CPU time efficiently and ensure all programs get a fair share of resources . Common scheduling algorithms include: First-Come First-Served : Processes are executed in the order they arrive to the CPU . Round Robin : Each process gets a fixed time slice in turn , cycling through all processes. Shortest Job First / Shortest Time Remaining : These methods identify the process with the shortest estimated runtime to be executed first . Multi-Level Feedback Queue : Uses multiple queues with different priority levels . Processes can be moved between queues to avoid starvation . Types of OS Different types of operating systems exist depending on the computer system and purpose : Multitasking OS : Allows a single computer to run multiple programs at the same time by quickly switching between them. Multi-user OS : Lets multiple users access the computer and its resources simultaneously , often via a network . Distributed OS : Manages a group of networked computers as a single system , sharing resources and tasks . Embedded OS : Designed for devices with specific functions , like microwaves or smart TVs , often with limited resources . Real-time OS : Provides immediate processing and responses for time-critical tasks , used in systems like medical devices or industrial robots . The BIOS The BIOS (Basic Input/Output System ) is firmware stored in ROM that helps the computer start up and manage initial communication between hardware and the operating system . During the start-up sequence , the BIOS first checks that essential hardware (e.g. the CPU and RAM ) is present and working correctly by running a Power-On Self Test (POST ). Signals are transmitted to all connected components . The BIOS then runs the bootstrap program to locate and load the operating system from a connected storage device into RAM . Once the OS is loaded , control is handed over to it, allowing the computer to become fully operational . Device Drivers A device driver is software that allows the operating system to communicate with hardware devices such as printers , graphics cards or keyboards . Hardware and the OS speak different ' languages ', so the driver translates OS instructions into commands the device can understand and vice versa. They are needed because, without drivers , the OS wouldn’t know how to control the hardware or use its features properly. Drivers also allow devices to work with different versions of an operating system and enable updates that improve performance or fix bugs . Virtual Machines A virtual machine is a software-based computer that runs an operating system and applications like a real computer , using part of the host computer’s hardware . It is isolated from the main system , so it can operate safely without affecting the host . Virtual machines are commonly used for testing software , running multiple operating systems and safely handling untrusted files . They provide flexibility , efficient hardware use and a secure environment for experimentation . Q uesto's K ey T erms Operating Systems: user interface, file management, user management Memory Management: paging, segmentation, virtual memory Interrupts: interrupt, interrupt service routine, stack Scheduling Algorithms: first come first serve, round robin, shortest job first, shortest time remaining, multilevel feedback queue Types of Operating System: multitasking, multi-user, distributed, embedded, real-time BIOS: ROM - power-on self-test (POST) Device Drivers: device driver Virtual Machines: virtual machine, thin clients, servers D id Y ou K now? New versions of the Android operating system used to be named alphabetically after sweet treats , from Cupcake , Donut and Eclair to Nougat , Oreo and Pie - the final named update in 2019 . 1.3 - Input, Output & Storage A-Level Topics 2.2 - Applications Generation