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Learn about application platforms such as augmented reality (AR), virtual reality (VR) and mixed reality (MR), websites and computer games. Resources based on Unit F161 (Developing Application Software) for the OCR Cambridge Advanced Nationals in Computing (H029 / H129) AAQ (Alternative Academic Qualification). Qualification: Cambridge Advanced Nationals in Computing (AAQ) Certificate: Computing: Application Development (H029 / H129) Unit: F161: Developing Application Software 1.1 - Application Platforms Watch on YouTube : Reality Platforms Websites Computer Games There are three types of application platforms you need to know, starting with devices based around merging technology and reality -augmented reality (AR ), virtual reality (VR ) and mixed reality (MR ). You also need to understand how websites and computer games are used as application platforms . You need to know the uses of these application platforms as well as their advantages and disadvantages . What You Need to Know Augmented Reality / Virtual Reality / Mixed Reality Augmented Reality (AR ) is technology that overlays digital images or information onto the real world . Virtual Reality (VR ) uses a computer-generated 3D environment that fully immerses the user , usually with a headset . Mixed Reality (MR ) is a blend of AR and VR where digital objects interact with the real world in real time . AR , VR and MR devices have a wide range of uses , the main three being educational , instructional and for research . Websites Websites can be used as platforms to deliver applications directly through a web browser , removing the need for users to install software on their device . This allows applications to be accessed easily across different devices and operating systems using an internet connection . There are four categories of websites to know: E-Commerce Instructional Educational Social Media Computer Games Computer (video ) games can be used as application platforms by combining software functionality with interactive gameplay and immersive environments . Games can increase user engagement and allow complex ideas , simulations or training activities to be delivered in a more intuitive and motivating way. Games are highly engaging , increasing user motivation and time spent using the application but game development is often complex , time-consuming and expensive , requiring specialist skills in a range of job roles . Q uesto's Q uestions 1.1 - Application Platforms: 1. Give the key features and uses for each reality-based device - AR , VR and MR . [4 marks each ] 2. Give three advantages and disadvantages of using a website as an application platform . [6 ] 3. A school is considering making a computer game application to encourage students to learn about rainforests . Consider two advantages and disadvantages of using computer games as an application platform in this scenario . [4 ] There are over 1 billion websites on the internet , but fewer than 20% are actively maintained , meaning most websites are abandoned , inactive or placeholder pages . D id Y ou K now? Topic List 1.2 - Devices

The list of topics in the 2020 OCR GCSE Computer Science specifications. OCR GCSE Computer Science (J277) These pages are based on the J277 OCR GCSE Computer Science specification . This website is in no way affiliated with OCR . Component One: Computer Systems OCR GCSE Key Term Generator Paper 1 Playlist on YouTube 1. Systems Architecture 1.1a - The CPU 1.1b - Registers & FE Cycle 1.2 - CPU Performance 1.3 - Embedded Systems 2. Memory & Storage 2.1 - Primary Storage 2.2 - Secondary Storage 2.3 - Units 2.4a - Number Systems 2.4b - Binary Addition & Shifts 2.4c - Character Storage 2.4d - Image Storage 2.4e - Sound Storage 2.5 - Compression 3. Networks 3.1a - Network Types & Performance 3.1b - Network Hardware & Internet 3.2a - Wired & Wireless networks 3.2b - Protocols & Layers 4. Network Security 4.1 - Network Threats 4.2 - Preventing Vulnerabilities 5. Systems Software 5.1 - Operating Systems 5.2 - Utility Software 6. Impacts 6.1a - Impacts of Technology 6.1b - Legislation Component Two: Computational Thinking, Algorithms and Programming Paper 2 Playlist on YouTube 1. Algorithms 1.1 - Computational Thinking 1.2 - Designing Algorithms 1.3 - Searching & Sorting Algorithms 2. Programming Fundamentals 2.1 - Programming Fundamentals 2.2 - Data Types 2.3 - Additional Programming Techniques 3. Producing Robust Programs 3.1 - Defensive Design 3.2 - Testing 4. Boolean Logic 4.1 - Boolean Logic 5. Languages & IDEs 5.1 - Languages & Translators 5.2 - Integrated Development Environment

The list of topics in the 2020 Eduqas (part of WJEC) GCSE Computer Science specification. Eduqas GCSE Computer Science These pages are based on the Eduqas GCSE Computer Science 2020 specification . 1. Hardware 1.1 - The Central Processing Unit (CPU) 1.2 - The FDE Cycle 1.3 - Primary Storage 1.4 - Secondary Storage 1.5 - Performance 1.6 - Additional Hardware 2. Logical Operators & Boolean 2.1 - Logical Operators 2.2 - Boolean Algebra 3. Networks & Security 3.1 - Network Characteristics 3.2 - Data Packets & Switching 3.3 - Network Topology 3.4 - Network Hardware & Routing 3.5 - Protocols 3.6 - 7-Layer OSI Model 3.7 - The Internet 3.8 - Cyber Threats 3.9 - Protection Against Threats 4. Data 4.1 - Number Systems 4.2 - Signed Binary 4.3 - Binary Calculations 4.4 - Arithmetic Shift 4.5 - Character Sets & Data Types 4.6 - Graphical Representation 4.7 - Sound Representation 4.8 - Compression 5. Data Organisation 5.1 - Data Structures & File Design 6. Operating Systems 6.1 - Operating Systems 6.2 - Utility Software 7. Principles of Programming 7.1 - Language Levels 8. Algorithms & Constructs 8.1 - Programming Principles 8.2 - Understanding Algorithms 8.3 - Writing Algorithms 8.4 - Sorting & Searching Algorithms 8.5 - Validation & Verification 9. Software Development 9.1 - IDE Tools 10. Program Construction 10.1 - Translators 10.2 - Stages of Compilation 10.3 - Programming Errors 11. Technological Issues 11.1 - Impacts of Technology 11.2 - Legislation Component 2 (Programming Exam) Python

Navigate between all Unit F160 (Fundamentals of Application Development) topics in the OCR Cambridge Advanced National in Computing (AAQ) specification. Qualification: Cambridge Advanced National in Computing (AAQ) Unit: F161: Developing Application Software Certificate: Computing: Application Development (H029 / H129) Unit F161: Developing Application Software These pages are based on content from the OCR Cambridge Advanced National in Computing (AAQ) specification . Unit F161 YouTube Playlist Topic 1: Application Software Considerations 1.1 - Application Platforms 1.2 - Devices 1.3 - Storage Locations This unit will be updated in summer 2026. Check here for the latest progress update. Topic 2: Data & Flow in Application Software 2.1 - Data Formats & Types 2.2 - Data Flow 2.3 - Data States Topic 3: API & Protocols 3.1 - Application Programming Interfaces (API) 3.2 - Protocols Topic 4: Application Software Security 4.1 - Security Considerations Topic 5: Operational Considerations 5.1 - Testing 5.2 - Types of Application Software Installation 5.3 - Policies Topic 6: Legal Considerations 6.1 - Legal Considerations

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

Learn about the benefits and drawbacks of virtualization, as well as about cloud storage and virtual clients. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification. 3.2 - Virtualisation Exam Board: OCR Specification: 2016 - Unit 1 What is virtualisation? Virtualisation is the creation of a virtual version of a device , software , operating system or server . These virtual versions can then be run on a different physical computer system , such as a powerful server . There are many different types of virtualisation . Storage virtualisation combines multiple separate storage devices into acting and appearing like a single , central storage system . Using storage virtualisation improves scalability as further devices can join the storage system if more space is required . It also simplifies the management of storage across the network. Server virtualisation allows one physical server to be divided into and host multiple virtual servers , each running separately . Each virtual server operates independently , handling its own operating system and applications . This allows for resources to be used more effectively and improves the scalability and versatility of the physical server . Client Virtualisation (Virtual Clients) Client virtualisation is when several virtual desktops are run on a single server - think back to the hypervisor from 3.1 . A virtual client is a full desktop environment where the processing happens remotely . For example, where an operating system is managed and hosted centrally but displayed locally on a different computer. These are often known as 'dumb clients ' because the server does the processing for it , meaning it can have minimal resources like a slow processor and little memory / storage . General Benefits & Drawbacks of Virtualisation Benefits of virtualisation: Costs are cheaper in the long-term because money is saved by not purchasing multiple physical devices . Money is also saved due to less cabling and lower power consumption . If set up efficiently, it can be used for higher performance at a lower cost - "Do more with less" . Programs can be tested in a secure environment before main-system deployment. Simplified response to recover after a disaster because only the server needs to be fixed. Drawbacks of virtualisation: If not set up efficiently, users could face serious performance issues , as fewer servers do more work. If a single physical system fails , the impact will be greater . Initial set up is complex , requires technical knowledge and can cost a lot. Easier for hackers to take more information at once as the data is stored in the same place. Benefits of client virtualisation: All data is stored in one central location , making backup and disaster planning easier to manage . The whole system can be managed , secured and updated from the server , rather than from each individual system. Hardware costs will be reduced because the virtual clients do not store or process their own data , meaning they can be of a low spec . Users can have multiple virtual machines and log in remotely (from anywhere with internet access ). Drawbacks of client virtualisation: Users will be unable to work if network connectivity is lost . There is a high strain on the server as the virtual clients do not store or process data themselves . An increased load on the server might result in poor performance for each client, especially with multiple connections . As the data is stored in one location , there are security risks of unauthorised access if the server is not adequately protected . Server Virtual Clients Cloud Technology 'The cloud ' is storage that is accessed through a network , primarily the internet. A cloud server is an example of storage virtualisation as data may be stored across multiple physical devices . There are three different types of cloud storage: Private cloud is where a business will have its own data centre that employees can access. This allows for flexible and convenient data storage and gives the business control over data management and security . Users of the private cloud will not usually have to pay individually for access - but the company will need to spend a lot of money on set up and maintenance . Public cloud uses third-party service providers such as Google Drive or DropBox to provide storage over the internet . Public cloud is usually a pay-for-use service , where businesses will pay for specific amounts that they need. Data management and data security is maintained by the cloud provider and the business is dependent on them providing constant access and deploying effective security measures. Hybrid cloud uses a mix of on-site storage (private cloud) and third-party (public cloud) services . Organisations can move workloads between private and public clouds as their specific needs and costs change . A benefit of hybrid cloud is that it gives an organisation greater flexibility and data storage options. As an example, a company could use on-site or private cloud storage to hold sensitive information and third-party, public cloud services to hold less important data . Q uesto's Q uestions 3.2 - Virtualisation: 1. What is the difference between server and storage virtualisation ? [ 2 ] 2a. What is a virtual client ? [ 1 ] 2b. What are the advantages and disadvantages of client virtualisation ? [ 8 ] 3. Explain any further general advantages and disadvantages of using virtualisation , not covered in your answer to 2b. [4 ] 4. Describe the differences between private , public and hybrid cloud storage. [6 ] 3.1 - Server Types Topic List 3.3 - Network Characteristics

Learn about on-site storage and cloud storage methods such as private, public, hybrid and community. Resources based on Unit F161 (Developing Application Software) for the OCR Cambridge Advanced Nationals in Computing (H029 / H129) AAQ (Alternative Academic Qualification). Qualification: Cambridge Advanced Nationals in Computing (AAQ) Certificate: Computing: Application Development (H029 / H129) Unit: F161: Developing Application Software 1.3 - Storage There are five types of on-site (local ) storage you need to know - file servers , network attached storage (NAS ) devices, portable storage devices, solid state drives (SSD ) and storage area networks (SAN ). In regards to cloud storage , you need to know the different locations (private , public , hybrid and community ) and types (file , object , block , elastic /scalable and cloud-based database services . You need to be aware of the characteristics , advantages and disadvantages of each storage location and type as well as the factors to consider when selecting a storage location and type . What You Need to Know On-Site Storage On-site storage is physically located at the same site as the user or organisation , such as in a building or office , rather than being stored over the internet in the cloud . It gives the organisation direct control over its storage devices and data . File Servers File servers are central computers that store files for users on a network , allowing multiple people to access and share data from one location . They make it easy to manage files , set user permissions and perform backups in one place . However, they can be expensive to set up and maintain , and if the server fails , all users may lose access . Performance can also slow down if too many users access it at once . NAS Devices A network attached storage ( NAS ) device is a dedicated storage unit connected to a network , designed specifically for storing and sharing files . It is usually simpler and cheaper than a full file server , making it suitable for small networks or home use as they are easy to install and useful for backups . But they are less powerful , have limited scalability and their performance depends heavily on the network speed . Portable Storage Devices Solid States Drives (SSDs) Portable storage devices , such as USB flash drives and external hard drives , are small , removable devices that connect directly to a computer . They are highly portable , affordable and convenient because they do not require a network connection . However, they are easy to lose or damage , can pose security risks if stolen or infected with malware , and typically have less storage capacity than larger systems . SSDs are storage devices that use flash memory instead of moving parts and are commonly found inside computers or used externally . They offer very fast read and write speeds , are durable , silent and energy efficient . On the downside, they are more expensive than traditional hard drives , often have lower storage capacity for the price , and can wear out over time due to a limited number of write cycles . Storage Area Networks A storage area network ( SAN ) is a high-speed network that provides access to consolidated storage , typically used by large organisations . It allows for extremely fast data access , high reliability and can be scaled to store very large amounts of data . However, SANs are very expensive to implement , complex to manage and require specialist knowledge to maintain . Cloud Storage Locations Cloud storage is a way of storing data on servers that are accessed over the internet , allowing users to access their files from anywhere with an internet connection . Private Cloud Public Cloud A private cloud is used by a single organisation , either hosted on-site or by a third party . It offers high levels of control , security and customisation , making it suitable for organisations handling sensitive data or needing to comply with data privacy regulations . However, it is expensive to set up and maintain and the organisation is responsible for managing and updating the system. A public cloud is provided by external companies and shared between multiple users or organisations over the internet . Examples include Google Drive and Dropbox . It is cost-effective , easy to access from anywhere and requires no maintenance by the user . It is also scalable if more space is required at a later time and convenient . However, it offers less control over data , may raise security and privacy concerns and depends on a reliable internet connection . Hybrid Cloud A hybrid cloud combines both private and public cloud storage , allowing data to be shared between them . Organisations can keep sensitive data in the private cloud while using the public cloud for less critical data . This provides flexibility , cost efficiency and better security control . However, it can be complex to set up and manage and integrating the two systems can be challenging . Community Cloud A community cloud is shared by several organisations with similar needs , such as schools or government departments . The advantages include cost sharing , tailored security and easier collaboration between organisations . However, it may be less flexible than other cloud types and there can be concerns about data privacy and management between different organisations . Cloud Storage Types Cloud storage types are the different ways data can be organised , stored and accessed in the cloud , with each type designed for different uses and performance needs . File Storage File storage organises data in a hierarchical structure of folders and files, similar to how files are stored on a personal computer . It is easy to understand and use , making it ideal for shared drives and everyday file access due to its compatibility with many systems. However, it can become slow or inefficient with very large amounts of data and scaling up can be more difficult compared to other cloud storage types. Object Storage Object storage stores data as individual objects , each with metadata and a unique identifier , rather than in folders. It is designed for large amounts of unstructured data such as images , videos and backups . Its advantages include excellent scalability , high durability and cost-effectiveness for large datasets . However, it is not suitable for applications that require fast, frequent updates and it can be harder to work with compared to traditional file systems. Block Storage Elastic / Scalable Storage Block storage splits data into fixed-size blocks and stores them separately . It provides very fast access and high performance , making it suitable for systems that need quick read/write operations . The advantages are speed , reliability and flexibility . However, it is more complex to manage , can be expensive , and does not include built-in file organisation like file storage. Elastic storage automatically increases or decreases capacity based on demand . It is commonly used in cloud environments where storage needs change frequently . The main benefits are flexibility , cost efficiency ( only pay for what you use ) and no need to predict storage requirements in advance . However, costs can become unpredictable and it relies heavily on a stable internet connection and provider availability . Cloud-Based Database Services These are cloud services designed specifically to store and manage structured data using databases . They handle tasks such as backups , updates and scaling automatically . The advantages include ease of use , automatic maintenance , scalability and high availability . However, they can be costly over time , offer less control than self-managed databases and may raise concerns about data security and vendor lock-in . Q uesto's Q uestions 1.3 - Storage: 1. Choose the most storage type and explain your answer. [ 4 each ] a. A school wants a central place where all teachers can save and share files . b. A photographer needs to carry thousands of photos between clients. c. A bank needs extremely fast storage for critical systems . d. A company wants storage that automatically grows as it stores more data . e. A video streaming company needs to store millions of videos . 2. For each scenario , recommend a storage location and explain why. [ 4 each ] a. A hospital storing confidential patient records . b. A small business with a limited budget . c. A university working with several partner colleges . d. A company that wants to keep sensitive data private but also use cheaper cloud storage . 3. Give two advantages and two disadvantages for each cloud storage type (file storage , object storage , block storage , elastic / scalable storage, cloud-based database services . [1 ] Every photo , video or file you upload to the cloud is often copied to multiple servers in different locations (this is called redundancy ). So if one server fails , your data can still be recovered . D id Y ou K now? 1.2 - Devices Topic List 2.1 - Data Formats & Types

Learn about the characteristics of networks, protocols, standards, the internet, TCP/IP stack, DNS servers, protocol layering, LANs, WANs, packet and circuit switching, network security and threats, firewalls, proxies, encryption, network hardware, client-server and peer to peer networks. Based on the OCR H446 Computer Science A-Level specification. Exam Board: OCR A-Level 3.3 - Networks Specification: Computer Science H446 Watch on YouTube : Purpose of networks (LAN & WAN) Protocols & standards Protocol layering & TCP/IP stack Domain Name System (DNS) Packet & circuit switching Network security threats Network security protection Network hardware Client-server & peer-to-peer This topic looks at how data is transferred between computer systems on networks , including the required devices , protocols , network types and potential security threats . Purpose of Networks A network is a group of connected computers that can share data , resources and communicate with each other . The main purpose of a network is to allow users to share files , hardware (like printers ), internet connections and other services efficiently . A Local Area Network (LAN ) covers a small geographical area , such as a single building or school , and is usually owned and managed by one organisation . A Wide Area Network (WAN ) covers a large geographical area , connecting multiple LANs through public or leased communication lines such as the internet . Protocols & Standards Protocols are sets of rules that define how data is transmitted and received over a network , ensuring that devices can communicate reliably . Standards are agreed specifications that ensure different hardware and software systems are compatible and can work together . They are needed so that networks remain interoperable , secure and efficient , regardless of the devices or manufacturers involved . Common network protocols include: HTTP /HTTPS is used for transferring web pages over the internet . FTP aids the transfer of files across a network . SMTP is used to send emails and IMAP /POP receive emails . TCP/IP is the core suite of protocols that controls how data is packaged , addressed , transmitted and received across networks . Protocol Layering & TCP/IP Stack Protocol layering is used to divide complex networking tasks into manageable sections , making systems easier to design , understand and troubleshoot . It also allows different technologies or protocols to work together , as each layer only interacts with the ones directly above and below it. The four layers are: Application layer : Provides network services to end users , such as web browsing (HTTP ) or email (SMTP ). Transport layer : Manages data transmission between devices, ensuring it arrives reliably and in the correct order (e.g. TCP , UDP ). Internet layer : Handles addressing and routing of data packets between networks using IP (Internet Protocol ). Link layer : Manages the physical connection between devices and controls how data is transmitted over the network hardware . Domain Name System (DNS) The Domain Name System ( DNS ) translates human-readable domain names (like www.csnewbs.com ) into IP addresses that computers use to identify each other on a network . When a user enters a web address , the request is sent to a DNS server to find the matching IP address . If the server doesn’t have it stored locally , it queries other DNS servers higher in the hierarchy until it finds the correct address . The IP address is then returned to the user’s device , allowing it to connect to the correct web server to access the requested web page . Packet & Circuit Switching Packet switching and circuit switching are methods of data transmission , describing how data is sent across a network from one device to another . With packet switching , data is split into small packets , each sent independently across the network and reordered at the destination . This makes efficient use of network resources and allows many users to share the same connections . However, packets can arrive out of order or be delayed , causing variable performance . With circuit switching , a dedicated communication path is established between two devices for the duration of a session , as in traditional phone networks . It provides a reliable and consistent connection with guaranteed bandwidth . The drawback is that it wastes resources , as the dedicated line cannot be used by others . Network Security Threats There is a range of potential threats associated with network use to be aware of, including the following: Hackers can attempt to gain unauthorised access to computer systems or networks , often to steal , alter or destroy data . Viruses are malicious programs that attach themselves to other files and spread , potentially damaging or deleting data . Denial of Service ( DoS ) attacks overload a network or website with traffic , making it unavailable to legitimate users . Spyware secretly monitors user activity and collects information such as passwords or browsing habits . An SQL injection involves inserting malicious SQL code into a database query to access or alter sensitive data . Phishing uses fraudulent emails or messages to trick users into revealing personal information . Pharming redirects users from legitimate websites to fake ones designed to steal login details or financial information . Network Security Protection Minimising or preventing network threats is vital and can be achieved with the following measures : Firewalls monitor and control incoming and outgoing network traffic , blocking unauthorised access while allowing safe communication . Secure passwords help protect user accounts by making it difficult for attackers to guess or crack them, especially when they are long and complex . Anti-virus software scans and removes malicious programs , such as viruses and worms , before they can damage files or systems . Anti-spyware software detects and removes spyware , preventing it from secretly collecting personal or sensitive information from a user’s device . Network Hardware A range of network hardware is required for devices to transfer data to another location , including the following: A modem converts digital data into analogue signals and back , allowing internet access over phone or cable lines . A router directs data between networks and assigns IP addresses to connected devices . Cables provide the physical connections between devices . A Network Interface Card ( NIC ) enables a computer to connect to a network . A Wireless Access Point ( WAP ) allows wireless devices to join a wired network via WiFi . On a local area network ( LAN ), hubs broadcast data to all devices , whereas switches send data only to the intended destination , improving network efficiency . Client-Server & Peer-to-Peer A client–server network has a central server that provides resources and services to client computers . It allows for centralised management , making it easier to back up data and enforce security policies . However, it relies heavily on the server - if it fails , users may lose access to resources . A peer-to-peer (P2P ) network has no central server ; instead, each computer can act as both a client and a server , sharing resources directly . It is cheap and easy to set up , making it suitable for small networks . The drawback is that it can be less secure and harder to manage , as data and security depend on individual users . Q uesto's K ey T erms Purpose of networks: local area network (LAN), wide area network (WAN) Protocols: protocol, standard, protocol layers, TCP/IP stack, application layer, transport layer, internet layer, link layer DNS: Domain Name System Switching: packet switching, circuit switching Network security: hackers, viruses, unauthorised access, denial of service, spyware, SQL injection, phishing, pharming, firewalls, secure passwords, anti-virus, anti-spyware Network hardware: modem, router, cable, NIC, Wireless Access Points, hub, switch Client-server & peer-to-peer D id Y ou K now? The first computer worm is considered to be Creeper (in 1971 ), which spread across ARPANET computers and displayed the message: “ I’m the creeper, catch me if you can! ”. A second program called Reaper was then created to delete Creeper , making it arguably the first antivirus . 3.2 - Databases A-Level Topics 3.4 - Web Technologies

Homepage for learning about computer science in school. Discover topics across GCSE and Level 3 IT subjects, plus programming languages including Python, HTML and Greenfoot. C omputer S cience Newb ie s Popular topics: Python Programming Application Development OCR Cambridge Advanced National in Computing (AAQ) A-Level Computer Science You are viewing the mobile version of CSNewbs. The site will appear better on a desktop or laptop . OCR A-Level (H446) GCSE Computer Science OCR GCSE (J277) Latest YouTube Video Latest Blog Post Links & Information YouTube Channel Last updated: Tuesday 30 th June 2026 Millions of visits since 2017! About CSNewbs

Learn about the devices used to host applications, including consoles, desktops, haptics, laptops, servers, smart devices, tablets / hybrid devices and wearables. Resources based on Unit F161 (Developing Application Software) for the OCR Cambridge Advanced Nationals in Computing (H029 / H129) AAQ (Alternative Academic Qualification). Qualification: Cambridge Advanced Nationals in Computing (AAQ) Certificate: Computing: Application Development (H029 / H129) Unit: F161: Developing Application Software 1.2 - Devices Watch on YouTube : Devices You need to know the characteristics of the eight types of devices shown below that application platforms run on . You must also understand the advantages and disadvantages of each device . YouTube video uploading soon What You Need to Know Devices Game consoles are designed specifically for playing video games , usually connected to a TV . Desktops are powerful and customisable personal computers designed for use at a desk . Haptic devices allow users to feel vibrations with touch . Game controllers and smartphones use haptics. Laptops are portable computers with a built-in screen and keyboard , suitable for work on the go . Servers are powerful computers on a network that process requests sent by other systems. Smart devices connect to a network allowing it to communicate with other devices and be controlled remotely . Tablets use a large touchscreen and are more portable than a laptop , ideal for browsing and media . A hybrid device is a laptop with a detachable screen . Wearable devices such as a smartwatch are worn on the body and often monitor the user's condition in real-time . Q uesto's Q uestions 1.2 - Devices: 1. Choose the most appropriate device and explain your answer. [3 each ] a. A graphic designer needs maximum performance and wants to upgrade components over time . b. A student needs a computer to take to lessons and complete homework . c. A hospital wants to provide files and applications to hundreds of staff members . d. A gamer wants the easiest and cheapest way to play the latest games . e. An engineer is designing a virtual reality training simulation . f. A fitness enthusiast wants to track their heart rate and daily exercise . g. A salesperson needs a lightweight device for presentations and note-taking . h. A family wants a device for watching movies and using apps around the house . 2. Compare the following pairs . For each comparison , explain one similarity , two differences and which you would recommend for a given purpose. [ 4 each ] a. Desktop vs Laptop b. Laptop vs Tablet/Hybrid c. Console vs Desktop d. Smart Device vs Wearable Check out the Shorts on the CSNewbs YouTube channel if you are interested in how video game consoles have evolved over time . There are separate videos for PlayStation , Xbox and Nintendo consoles. D id Y ou K now? 1.1 - Application Platforms Topic List 1.3 - Storage Locations

Learn about the Central Processing Unit (CPU), the four components within and Von Neumann architecture. Based on the 2020 Eduqas GCSE (WJEC) specification. Exam Board: Eduqas 1.1 The Central Processing Unit (CPU) Specification: 2020 The Central Processing Unit ( CPU ) is the most important component in any computer system. The purpose of the CPU is to process data and instructions by constantly repeating the fetch - decode - execute cycle . CPU Components The control unit directs the flow of data and information into the CPU. It also controls the other parts of the CPU . ALU stands for ‘ Arithmetic and Logic Unit ’. It performs simple calculations and logical operations . The registers are temporary storage spaces for data and instructions inside the CPU. The registers are used during the FDE cycle . Five essential registers are explained in 1.2 . Cache memory is used to temporarily store data that is frequently accessed . Cache memory is split into different levels . Level 1 and level 2 (L1 & L2) are usually within the CPU and level 3 (L3) is just outside it. See 1.3 and 1.5 for more information about cache. You should know: The control unit is also known as the controller and cache memory is sometimes called internal memory . Computer Architecture The way a computer is designed and laid out is known as its architecture . The most common type of computer architecture is Von Neumann . Von Neumann Architecture The CPU is the most important component in Von Neumann architecture as it is constantly fetching and decoding instructions from RAM and controlling the other parts of the system . Von Neumann architecture also stores both instructions and data in memory . Being able to store programs in memory allows computers to be re-programmed for other tasks - this enables it to multitask and run several applications at the same time. Data input and output is another key feature of this architecture. An alternative architecture is Harvard , which features the control unit as the most essential component. Q uesto's Q uestions 1.1 - The Central Processing Unit (CPU): 1a. What does 'CPU ' stand for ? [1 ] 1b. What is the purpose of the CPU ? [ 2 ] 2a. Draw a diagram of the CPU , use the same symbols as shown on this page. [ 4 ] 2b. Label the four main components of the CPU. [ 4 ] 3. Describe the purpose of: a. The Control Unit [ 2 ] b. The ALU [ 2 ] c. The registers [ 2 ] d. Cache memory [ 2 ] 4a. Describe the key features of Von Neumann architecture . [ 3 ] 4b. Explain why storing data in memory is important. [ 1 ] 4c . State an alternative architecture . [ 1 ] Theory Topics 1.2 - The FDE Cycle

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