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3.1a: Network Types & Performance Exam Board: OCR Specification: J277 What is a network? A network is more than one computer system connected together allowing for communication and sharing of resources . 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 Wide Area Network Client-Server Network Clients make requests to a server , the server manages that request and responds. For example, if the user (client) makes a request to access www.bbc.co.uk to a web server. Large services like Amazon and Google will need very powerful servers to handle millions of requests a second. The client is completely dependent on the server to provide and manage the information. The server controls network security , backups and can be upgraded to manage higher demand. Advantages: The network can be controlled centrally from the server to easily backup data and update software . Hardware, software and resources can be shared across the network, such as printers, applications and data files . The network allows for improved scalability , meaning more clients can be easily added to the central server . Disadvantages: Large amounts of traffic congestion will cause the network to slow down . If a fault occurs with the server then the whole network will fail . IT technicians may be required to manage and maintain the network . Malware , such as viruses, can spread quickly across the network. Peer-to-Peer Network For peer-to-peer networks , data is shared directly between systems without requiring a central server . Each computer is equally responsible for providing data. Peer to peer is optimal for sharing files that can then be downloaded. Disadvantages: Without a dedicated server there is no central device to manage security or backups . Backups must be performed on each individual system. Computer performance will decrease with more devices connected to the network, especially if other machines are slow. Advantages: This is a simpler network than client-server to set up as no server is required . Clients are not dependent on a server . Perfect for quickly sharing files between systems , such as downloading media files. 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 . The network infrastructure of a LAN (such as servers and routers) is usually owned and managed by the network owner . A wide area network (WAN ) has computer systems situated geographically distant to each other, possibly across a country or even across the world . WANs often use third party communication channels , such as connections by internet services providers like BT or Virgin Media. Other network types do exist, such as a Metropolitan Area Network (MAN ) for computer systems connected across a town or city or a Personal Area Network (PAN ) for devices connected and used by an individual . Data Packets When sending data across a network, files are broken down into smaller parts called data packets . Whole files are too large to transfer as one unit so data packets allow data to be transferred across a network quickly . Each packet of data is redirected by routers across networks until it arrives at its destination. Data packets may split up and use alternative routes to reach the destination address. When all the packets have arrived at the destination address the data is reassembled back into the original file. Contents of a Data Packet: Header Payload Trailer Source address Destination address Packet number Protocol The data itself A checksum - this is a calculation on the data to see if any errors or corruption have occurred during transmission . What is a network topology? Network topology refers to layout of computer systems on a local network . Devices in a network topology diagram are often called 'nodes' . Two types of typology are star and mesh . Star Topology Each computer system is connected to a central device , usually a hub or switch . How it works: Each computer system is connected to the central hub or switch and transfers its data packets there. The hub or switch looks at the destination address and transfers the packets directly to the intended computer. Advantages: A star topology has improved security because data packets are sent directly to and from the hub / switch in the centre and not necessarily all devices like in a bus or ring topology. New systems can be attached directly to the central system so the network doesn't need to be shut down . System failures of attached computers won't usually cause complete network failure. Transfer speeds are generally fast in a star topology as there are minimal network collisions . Disadvantages: Extra hardware (the hub or switch) is required to be purchased, installed and maintained. If the central system (the hub or switch) fails then the whole network will be unusable until the error is fixed. Mesh Topology In a full mesh network, each computer system is connected to every other computer system . There is also a partial mesh network where only some nodes (e.g. a printer) are connected to every other node. How it works: Data packets are transferred to the destination address along the quickest path , travelling from node to node. If a pathway is broken , there are many alternative paths that the packets can take. Advantages: If one cable or system fails then data packets can take an alternative route and still reach the destination address. Because of the large possible number of systems and connections, a mesh topology can usually withstand large amounts of data traffic . New systems can be added to the network without disrupting the entire topology . Disadvantages: Because of the possibly large amount of cables required (especially in a full mesh topology) this network layout can be expensive to install and maintain . Redundant cabling should be avoided - this is when cables are connected between systems that won't ever need to communicate . Performance There are several different factors that can affect the performance ( speed ) of a network, such as: The bandwidth available * Interference (e.g. thick walls) Applications being used Number of users at the same time Distance to travel / signal strength Server / CPU Performance Number of data collisions Amount of data to transfer * Bandwidth is the maximum amount of data that can be sent across a network at once . Q uesto's Q uestions 3.1a - Network Types & Performance: 1a. Describe the difference between a LAN and WAN . [2 ] 1b. Give an example of how a LAN and a WAN could each be used . [ 2 ] 2 a. Describe how peer-to-peer networks and client-server networks function. 2b. Give one use for both types of network. 3. Draw and label diagrams of client-server , peer-to-peer , star and mesh networks. [8 ] 4. An office currently uses a star topology but is considering changing to a mesh topology . Describe two advantages and two disadvantages of both topologies. [ 8 ] 5. State five factors that could affect the performance of a network . [5 ] 2.5 - Compression 3.1b - Network Hardware & Internet Theory Topics

11.2: Legislation Exam Board: Eduqas / WJEC Specification: 2020 + 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. 2. Only 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. 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. 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 . 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. Creative Commons (CC) Licensing A CC licence allows people to share their copyrighted work while still retaining rights to the material . There are different types of licence that specify exactly what can and can't be done to the copyrighted material. For example: An attribution licence allows copyrighted material to be edited and distributed but the original owner must be credited . A non-commercial licence allows copyrighted material to be shared and edited but no profit must be gained through its distribution. CC licences are not automatically given , they must be granted by the copyright owner . To ensure you are not illegally using copyrighted work change the Tools and Licence setting when using Google Images to filter work with CC licenses applied . Telecommunications Regulation Act (2000) This act allows organisations to lawfully monitor communications made online and on the phone by employees while at work . All users of the network should be aware that their communication is being monitored when they are using emails , the internet or telephone calls . The act was introduced to ensure that employees are using the computer systems for the correct purpose , to prevent illegal activity and to monitor staff performance . Codes of Conduct One way that organisations try to ensure that staff are held to professional standards and display appropriate behaviour is to create a code of conduct . This is a set of rules or requirements that employees must follow or they may be punished, such as a temporary ban from the network or being fired. There are two types of codes of conduct: Formal codes of conduct are a set of written rules that clearly state expected behaviour , such as what employees can access online at work . Schools may have this too, and you might have to sign a document at the start of the year before you can use the computers. Informal codes of conduct are used by small organisations where there might not be a written set of rules , but newer employees follow the habits and expectations of senior members of staff. This is harder to monitor but provides a more relaxed working environment. Q uesto's Q uestions 11.2 - 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 4 principles of the Computer Misuse Act (1990) . [3 ] 3. Describe the purpose of the Freedom of Information Act (1990) and state an example of a freedom request . [ 3 ] 4a. What is the purpose of RIPA (2000) ? [ 2 ] 4b. Describe 3 actions that RIPA (2000) allows the government / police to do . [ 3 ] 5a. What is the purpose of the Copyright, Designs & Patents Act (1988) ? [ 2 ] 5b. Describe 3 actions that CDPA (1988) prohibits . [ 3 ] 6a. What is a Creative Commons ( CC ) licence ? [ 2 ] 6b. Describe 2 types of CC licence . [ 4 ] 7a. What is the purpose of the Telecommunications Regulation Act (2003) ? [ 2 ] 7b. Describe 3 reasons why this act was introduced . [ 3 ] 8a. What is the purpose of a code of conduct ? [ 2 ] 8b. Describe the difference between formal and informal codes of conduct . [ 2 ] 11.1 - Impacts of Technology Theory Topics

Frequently Asked Questions about Computer Science Newbies Who made CSNewbs? My name is Mr Pulsford . I am from London and I am currently the Head of C omputer Science at a secondary school in South Yorkshire , England . When and why did you make this? I wanted to make a resource that my students could access outside of the classroom . I was working on a paid summer project at G o o g l e in London in 2016 when I was inspired to start the site. I've been updating it ever since as much as I can, outside of lessons and life. I made CSNewbs to support students in lessons and at home because Computer Science can be a tricky subject and many websites are too technical or peripheral . Which courses does CSNewbs cover? The ' GCSE ' section follows the OCR specification ( 2020 ) and Eduqas / WJEC specification ( 2020 ). The ' CTech ' section follows the OCR Cambridge Technicals Level 3 IT 2016 specification for Unit 1 (Fundamentals of IT) and Unit 2 (Global Information). The ' Programming ' section contains material for Python , HTML , Greenfoot and others. The ' KS3 ' section covers basic Computer Science topics aimed at Year 7 - 9 students . Do the exam boards pay you money for this? CSNewbs is not affiliated with any exam board , financially or otherwise . The content on this site has been independently created by closely following the publicly released specifications by Eduqas and OCR. Can I get a level 9 / distinction just from CSNewbs? The content on this website is of high-quality and should be used to guide students towards a better understanding of the course's content. Like all resources however , it should be supported with a range of appropriate material and sound classroom teaching . CSNewbs makes no miraculous claims linking content use and final exam results. How did you make this website? CSNewbs.com was created and is maintained using Wix . What's the deal with copyright? CSNewbs is protected by copyright , and copy / paste features have been disabled on the site. All images have either been created by myself or used from Wix's copyright-free vector gallery / their stock image library . Embedded videos are linked to content from the CSNewbs YouTube page. If you think any content on this site infringes a copyright-protected work , please email me, and I will make immediate changes . I don't see any adverts, how are you making money? You're right, there are no adverts and I intend to keep it that way. I don't make and never have made any money from this website. Can you add Unit 3 / OCR A-Level / something else? The site continues to expand over time with new content . The eventual aim is to cover every exam board for GCSE Computer Science but that will take a lot of time! How come something on the site isn't working at my school? Your school's IT administrators may have blocked some elements such as JavaScript or embedded YouTube videos . The videos can be watched directly on YouTube (if not blocked on your school network). Who is the robot? The robot is called Questo . It's the site mascot and it appears on most pages to ask you questions about the content (' Questo's Questions '). It used to have a body but since 2020 it's just a head. I can't believe one person made this whole site while teaching and the rest, what are your long-term plans? If you work for an exam board or educational resource organisation , and your organisation has opportunities available , please send me an email. How can I contact the creator of CSNewbs? The contact email is: Privacy Policy There are social media pages for CSNewbs but with busy times recently they are rarely updated :

Algorithms Pseudocode 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 real 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 flowchart A flowchart can be used to visually represent an algorithm. The flowchart symbols are: Algorithm Example example Pseudocode {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 Stop Flowchart

Here you can find a list of tags. Click a tag to see how to use it. Tags for Eduqas GCSE:

4. Remove Objects Greenfoot Tutorial 1. Removing Objects Watch on YouTube: Open the editor for your main character . Underneath the if statements for using the arrow keys is where we type the removal code . If you have chosen a different collectible object, type the exact name of that class instead of Orange (e.g. Apples or Ants). 2. Add Danger to your Game Use the same code as you did earlier but change the class (instead of Orange. class I have chosen Sheep. class ). Time to code your main character to be removed if they are touched by the enemy objects ! Open the editor for your enemy class . The removal code is placed beneath the code you have already written. Check out the extension page if you want the game to stop when the main character is removed. < Part 3 - Random Movement Part 5 - Play Sounds >

OCR Cambridge Technicals IT Level 3 Unit 1: Fundamentals of IT 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 . LO1 (Computer Hardware ) 1.1 - Computer Hardware 1.2 - Computer Components 1.3 - Types of Computer System 1.4 - Connectivity 1.5 - Communication Hardware 1.6 - Hardware Troubleshooting 1.7 - Units of Measurement 1.8 & 1.9 - Number Systems & Conversion LO2 (Computer Software ) 2.1 - Types of Software 2.2 - Applications Software 2.3 - Utility Software 2.4 - Operating Systems 2.5 - Communication Methods 2.6 - Software Troubleshooting 2.7 - Protocols LO3 (Networks & Systems ) 3.1 - Server Types 3.2 - Virtualisation 3.3 - Network Characteristics 3.4 - Connection Methods 3.5 - Business Systems LO4 ( Employability & Communication ) 4.1 - Communication Skills 4.2 - Communication Technology 4.3 - Personal Attributes 4.4 - Ready for Work 4.5 - Job Roles 4.6 & 4.7 - Bodies & Certification LO5 (Issues & Security ) 5.1 - Ethical Issues 5.2 - Operational Issues 5.3 - Threats 5.4 - Physical Security 5.5 - Digital Security 5.6 - Data & System Disposal

1.1 - Holders of Information Exam Board: OCR Specification: 2016 - Unit 2 Categories of Information Holders Organisations that store and process information can be put into seven different categories : Business A business will hold information on all of its employees , including their date of birth, address and financial information , allowing them to be paid at the end of each month. Businesses will also hold commercial information about their organisation such as profits and losses, product descriptions and historical data . Many companies may record information about their competitors and general marketing data. Government The government will hold a huge amount of information about all citizens in the country including financial earnings, tax paid, births and deaths . The electoral roll holds information about addresses . A national census is taken every 10 years in the UK (the next census is in 2021) that records extensive data about everyone living in the country. The government also stores information about other countries and shares some of this publicly, such as the Foreign Office posting travel advice . Individual Education Educational organisations , such as schools, colleges and universities will hold information about current and past students as well as staff. Student information such as addresses, attendance records and examination history will be recorded, as well as contact information for parents and guardians. Teacher information will be stored too, as well as students that previously attended the institution, even for a number of years after they have left. An individual will hold information about themselves , either in their head or on paper or electronically. This includes their name, date of birth, address, usernames and passwords . Individuals will store information of others , such as phone numbers, social media details and email addresses . Other information will be about organisations , such as the address of their favourite restaurant, opening hours of the local cinema or the telephone number from a catchy advert. Healthcare Healthcare services , like the NHS in the United Kingdom, will hold entire medical histories for each civilian in the country. This includes basic personal information such as current address and date of birth but much more detailed data too like previous illnesses and operations, blood type, allergies and prescriptions . The data stored by healthcare organisations is usually confidential and should not be shared by anyone other than the citizen in question. Charity & Community Charities may hold financial information of donors who give money to them, as well as information about the different projects that the donations are funding. Charities such as the British Heart Foundation might have physical addresses on the high street so information may be kept about the shops too. Community organisations like sport centres or religious institutions may hold information on members and matches, meetings or events . Comparison of Locations The location of systems and data affects access speed and network quality . The digital divide is the gap between people who do and do not have easy access to computers and networks . Developed vs. Developing Countries Developed countries , like areas of Western Europe, North America and East Asia, have a more developed technology and industry base with more funding available for information infrastructures such as cabling and high-speed access . Developing countries , like areas of Africa and Central Asia, have unstable governments and slower access (if any) to the internet . Less money is spent on technology and improving broadband speed and expensive equipment like computers cannot be purchased on low wages . Urban vs. Rural Urban locations like towns and cities have a high population density . Because there are so many people, councils and IT companies will spend a lot of money on internet infrastructure such as cabling and installing high-speed lines . In Rural locations like the countryside, the population is sparse and settlements may be far apart so internet access is poorer and broadband speeds are slower . This means accessing information on the internet is more difficult . Internet Access from Remote Locations Remote locations (such as the countryside or difficult-to-reach areas like mountains or deserts) might have limited internet access . Fast fixed broadband is expensive to install and many providers simply won't invest in rural areas as it is not economically viable . Some areas, usually those with a very small or temporary population, might have no fixed internet access which will make it difficult for an individual or organisation to communicate or work online. Many remote locations have some form of internet but download speeds will be slow or interrupted due to intermittent connection . This makes it difficult to work online and could take a long time to access webpages or document stores. Alternatives to fixed broadband in remote locations include mobile broadband and satellite broadband . Mobile broadband is generally not designed for home use and would be very expensive for everyday use , plus the remote location will generally mean mobile coverage could also be weak . Satellite broadband requires a dish with an unrestricted view of the sky. Satellite broadband has a relatively high internet speed but will cost a lot to install and has a high latency (more chance of experiencing lag). Q uesto's Q uestions 1.1 - Holders of Information: 1a. State the 7 categories of information holders . [7 ] 1b. For each of the 7 categories , briefly describe 3 different pieces of information that may be stored by the information holder. For example, a charity may store the financial information of donors. [3 each ] 2. What is the digital divide ? [2 ] 3. Describe the differences in information access for the following locations : a. Developed vs. developing countries b. Urban vs. rural areas c. Remote locations [4 each ] Topic List 1.2 - Storage Media

Exam Board: OCR 3.1b - Big O Notation Specification: A-Level 2015 An instruction set is a list of all the instructions that a CPU can process as part of the FDE cycle . CPUs can have different sets of instructions that they can perform based on their function. The two most common instruction sets are the simpler RISC (Reduced Instruction Set Computer ) and more complicated CISC (Complex Instruction Set Computer ). Instruction Sets This page is still being updated. Graphical Processing Unit What is cache memory? Cache memory is temporary storage for frequently accessed data . Cache memory is very quick to access because it is closer to the CPU than other types of memory like RAM . Multicore & Parallel Systems What is cache memory? Cache memory is temporary storage for frequently accessed data . Cache memory is very quick to access because it is closer to the CPU than other types of memory like RAM . Multicore & Parallel Systems What is cache memory? Cache memory is temporary storage for frequently accessed data . Cache memory is very quick to access because it is closer to the CPU than other types of memory like RAM . Q uesto's Q uestions 3.1b - Big O Notation: 1. What is cache memory ? [ 2 ] 3.1a - Algorithm Design Theory Topics 3.1c - Stacks, Queues & Lists

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