Learn about network devices such as a switch, router, modem and NIC. Also learn about internet terms and services including DNS and the Cloud. Based on the J277 OCR GCSE Computer Science specification (first taught from 2020 onwards). 3.1b: Network Hardware + The Internet Exam Board: OCR Specification: J277 Watch on YouTube : The Internet Network Hardware DNS Servers The Cloud Network Devices 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. Wireless Access Point A Wireless Access Point provides a link between wireless and wired networks . It creates a wireless local area network that allows WiFi-enabled devices to connect to a wired network. Examples of a wireless access point in a public space could be a WiFi or Bluetooth hotspot , for example a WiFi hotspot in a coffee shop or airport to provide access to the internet. A wireless access point may be a separate device or built into another device such as a router. Router Routers are used to transfer data packets between networks . Routers receive data packets and use the IP address in the packet header to determine the best route to transmit the data. Data is transferred from router to router across the internet towards the destination. A router stores the IP address of each computer connected to it on the network and uses a list called a routing table to calculate the quickest and shortest route to transfer data. Switch A switch is used to connect devices together on a LAN . It receives data packets from a connected node, reads the destination address in the packet header and forwards the data directly to its destination. A switch will generate a list of the MAC addresses of all devices connected to it when it receives data , and must scan for a matching destination address before sending. An alternative to a switch is a hub but a hub is slower and less secure as it forwards a copy of received data to all connected nodes . Network Interface Controller / Card A Network Interface Controller (NIC ) commonly also known as a Network Interface Card is an internal piece of hardware that is required for the computer to connect to a network . The card includes a MAC address which is used when sending data across a LAN . An ethernet cable is plugged into the network card to allow data to be exchanged between the device and a network. A NIC used to be a separate expansion card but is now typically embedded on the motherboar d . Transmission Media Although not technically a device, the communication channel along which data is transferred will affect performance . Three common types of transmission media include: Ethernet cables - used typically on a LAN to transfer data between nodes and hardware such as switches. Examples include Cat5e and Cat6. Fibre Optic cables - very fast but more expensive and fragile cables typically used to send data quickly along a WAN . Data is sent as pulses of light . Coaxial cables - older , slower , copper cables that are not used as much in modern times as they can be affected by electromagnetic interference . The Internet The internet is a global network of interconnected networks . The world wide web (WWW ) is not the same as the internet. It is a way of accessing information , using protocols such as HTTPS to view web pages . Servers provide services on the internet , such as a web server which responds to the web browser (client) request to display a web page . The web server processes the client request to prepare the web page and return it so the web browser can display it to the user . A website must be hosted (stored) on a web server so that it can be accessed by others using the internet . A unique domain name (e.g. csnewbs.com) must be registered with a domain registrar – this is a company that checks the name is valid and not already taken . What is the Internet? DNS Servers A DNS ( Domain Name System ) server stores a list of domain names and a list of corresponding IP addresses where the website is stored. The first thing to understand is that every web page has a domain name that is easy for humans to remember and type in (such as www.csnewbs.com ) as well as a related IP address (such as 65.14.202.32) which is a unique address for the device that the web page is stored on. The steps taken to display a web page: 1. A domain name is typed into the address bar of a browser . 2. A query is sent to the local DNS server for the corresponding IP address of the domain name . www.facebook.com 3. The local DNS server will check if it holds an IP address corresponding to that domain name. If it does it passes the IP address to your browser . 66.220.144.0 4. The browser then connects to the IP address of the server and accesses the web site . If the local DNS server does not hold the IP address then the query is passed to another DNS server at a higher level until the IP address is resolved. If the IP address is found, the address is passed on to DNS servers lower in the hierarchy until it is passed to your local DNS server and then to your browser. Cloud Storage The cloud refers to networks of servers accessed on the internet . Cloud computing is an example of remote service provision . Cloud servers can have different purposes such as running applications , remote processing and storing data . When you store data in 'the cloud', using services such as Google Drive or Dropbox, your data is stored on large servers owned by the hosting company . The hosting company (such as Google) is responsible for keeping the servers running and making your data accessible on the internet . Cloud storage is very convenient as it allows people to work on a file at the same time and it can be accessed from different devices. However, if the internet connection fails , or the servers are attacked then the data could become inaccessible . Cloud Storage Characteristics: ✓ - Huge CAPACITY and you can upgrade your subscription if you need more storage. ✓ / X - Cloud storage is difficult to rank in terms of PORTABILITY , DURABILITY and ACCESS SPEED because it depends on your internet connection. A fast connection would mean that cloud storage is very portable (can be accessed on a smartphone or tablet) but a poor connection would make access difficult . ✓ - Cloud storage is typically free for a certain amount of storage. Users can then buy a subscription to cover their needs - Dropbox allows 2 GB for free or 2 TB for £9.99 a month. Q uesto's Q uestions 3.1b - Network Hardware & Internet: 1a. Explain how a switch works. [ 2 ] 1b. Describe the purpose of a router . [ 2 ] 1c. State what WAP stands for and why it is used . [ 2 ] 1d. State what NIC stands for and why it is required . [ 2 ] 1e. State the differences between the three main types of transmission media . [ 3 ] 2a. State what the internet is and how it is different to the world wide web . [ 2 ] 2b. What is web hosting ? [ 2 ] 3a. What is a DNS server ? [ 2 ] 3b. Describe, using a mix of text and icons / images , how a DNS server is used to display a web page . [5 ] 3c. Describe how a DNS server searches for an IP address if it is not found on the local DNS server . [ 2 ] 4a. Describe what cloud computing is. [ 2 ] 4b. State two advantages and two disadvantages of the cloud . [ 4 ] 3.1a - Network Types & Performance Theory Topics 3.2a - Wired & Wireless Networks

Learn about different types of tools used in the data analysis process including data visualisation, data cleaning and GIS. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification for Unit 2 (Global Information). 3.5 - Data Analysis Tools Exam Board: OCR Specification: 2016 - Unit 2 The fifth stage of data analysis is to select the most appropriate tools to analyse the collected data. The method(s) selected will depend on the type of project and the established objectives. Data Tables Databases are often split into tables to be easier to update , view and manipulate . For example, a supermarket database may include a table of product information, another table of suppliers and another for actual stock levels. Separating the data into tables allows for simpler editing and also allows for the display of basic patterns . For example, looking at a table of stock levels in a supermarket can quickly show which products need to be ordered in as they are close to selling out. Data tables allow for the most simple form of pattern discovery and are a good method of speedy, short-term data analysis . However they present data in its current format and cannot show change or trends over time - a product may have a high stock level because it is popular and has just been ordered in, rather than because no-one is buying it. A simplified data table for a supermarket. Visualisation of Data Visualising data (by producing a chart or graph of collected data for example) makes it easier for an audience to see trends and patterns . Visualising data, like the bar chart to the right of the supermarket table from the tool above, makes it easier to understand and quicker to interpret . In this example, It is easier to see using the chart that steak pies are low in stock and should be re-ordered soon. A bar chart of the supermarket data table. Trend & Pattern Identification This tool links heavily to visualisation of data in allowing trends and patterns to be viewed as a visual format - such as producing a line graph of last year’s stock sales. Statistical analysis allows data analysts to examine numerical data and, if done correctly, can highlight relationships between different data elements - such as the price of a product and how many have been sold. Discovering links between variables is known as regression analysis . Data Cleaning Data cleaning ensures that any stored data is up-to-date and accurate , in accordance with the Data Protection Act ( 2018 ). Forms of data cleaning include removing customers who have not made a purchase in a certain amount of time (e.g. two years) and periodically checking that user addresses are up to date. Data cleaning would reduce the size of any data table by removing redundant, incorrect or unnecessary data . This would make it easier to work with the data table and would improve the data quality by removing erroneous and irrelevant data. GIS / Location Mapping Geographic Information Systems (GIS ) can be used to add geographic data to any analysis. For example, an organisation can track the geographical location of items or staff e.g. tracking the movement of shipping containers around the world to see production flow. This also works for courier services to see delays and delivery times in real-time . Q uesto's Q uestions 3.5 - Data Analysis Tools: 1. Describe how Fresh Food UK, from the question in 3.4 , could use each of the data analysis tools when trying to determine and present the most profitable stores across the country in the past year . a. Data Tables [3 ] b. Visualisation of Data [3 ] c. Trend & Pattern Identification [3 ] d. Data Cleaning [3 ] e. GIS / Location Mapping [3 ] 3.4 - Stages of Data Analysis Topic List 3.6 - Information Systems

Learn about different methods of wired and wireless connection methods including Bluetooth, satellite and microwave. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification. 1.4 - Connectivity Exam Board: OCR Specification: 2016 - Unit 1 For computers to communicate with other devices and share data a form of connection is required. Wired Connections Copper Cables Copper cables are a cheaper type of wired internet connection that may be poorly insulated and therefore susceptible to electromagnetic interference . Copper cables are more likely to suffer from attenuation (network distortion ). However, they are malleable (easier to bend) and less likely to break than other cables such as fibre optic. They have a lower bandwidth - cannot transmit as much data at once - than fibre optic cables. Fibre Optic Cables Fibre optic cables are a very fast but expensive type of wired internet connection. Signals are transmitted as waves of light through a glass rod . Because of this fibre optic cables are not affected by electromagnetic interference and suffer less from attenuation . Fibre optic cables have a higher bandwidth - they can transfer more data at one time over a long distance than copper cables but they are more fragile . Wireless Connections Bluetooth Bluetooth is a temporary short-range communication between two 'paired ' devices within a limit of about 10 metres . The required close proximity is a disadvantage , however a plus is that no other hardware is required for a connection. An example is the pairing of headphones to a smartphone to listen to music. Infrared Infrared networks have largely been replaced by Bluetooth or WiFi connections because infrared networks require devices to be in direct line of sight . Infrared is still used by some devices, such as remote controls , to transmit signals to a TV, but it only works across short distances . Microwave Microwave connections use radio waves to send signals across a large area via microwave towers . It can transmit a large amount of data but antennas must be in the line of sight of each other with no obstructions . Microwave connections are affected by bad weather , leading to higher chances of attenuation (network distortion ). Laser Satellite GSM / 5G Although not common, laser connections can send data between devices that are in the line of sight of each other as long as there are no barriers . Laser connections can transmit data up to 2km but bad weather severely affects the transmission rate. Laser connections can be used in space as there are fewer barriers between the satellites. Satellite networks use point-to-multipoint communication by using satellites above the Earth's atmosphere that receive a transmission and rebroadcast them back to Earth. Because of the distance between the communication device and the satellite (roughly 35,000km), there is a delay between data transmission and it being received. See 3.4 for more information on satellite networks . GSM (Global System for Mobile communications ) is a technology for allowing mobile phones to connect to a network for calls and text messages. Advances in mobile technology are classified by generations such as 4G and 5G (the current generation). Each generation is generally faster, more secure and allows for new opportunities. See 3.4 for more information on cellular networks . Q uesto's Q uestions 1.4 - Connection Methods: 1. Compare the differences between copper and fibre optic cables (possibly in a table) by the following features: a. Price b. Bandwidth c. Inteference d. Attenuation e. Malleability / Fragility [2 each ] 2. Describe each of the different types of wireless connection . Try to list 1 advantage and 1 disadvantage of using each type. a. Bluetooth b. Infrared c. Microwave d. Laser e. Satellite f. GSM / 5G [5 each ] 1.3 - Computer System Types Topic List 1.5 - Communication Hardware

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

Learn about the differences between CISC and RISC processors, GPUs and multicore and parallel systems. Based on the OCR H446 Computer Science A-Level specification. Exam Board: OCR A-Level 1.2 - Types of Processor Specification: Computer Science H446 Watch on YouTube : CISC and RISC GPUs Multicore & parallel systems Instruction Sets An instruction set is the complete list of machine code instructions a CPU is designed to execute as part of the FDE cycle . CISC (Complex Instruction Set Computer ) CPUs have a large set of complex instructions , so tasks can be achieved in fewer lines of code , but some instructions take multiple clock cycles . RISC (Reduced Instruction Set Computer ) CPUs use a smaller set of simple instructions , each designed to execute in a single clock cycle , making execution faster but sometimes requiring more instructions overall . GPUs A GPU (Graphics Processing Unit ) is a co-processor with thousands of smaller cores designed for parallel processing . This is in contrast to the CPU , which has fewer but more powerful cores . GPUs are used for rendering images , animations and video for fast , realistic graphics in games and multimedia . Because of their ability to handle many calculations at once , GPUs are widely used for non-graphical purposes too, such as machine learning , scientific simulations , data analysis and cryptocurrency mining . Multicore & Parallel Systems A multicore processor has multiple independent cores on a single CPU chip . Each core can carry out its own FDE cycle , so tasks can be split up , enabling multitasking and faster processing . However, only software designed to use multiple cores will benefit from this increased performance . A parallel system uses multiple processors (or cores ) working together on the same problem at the same time . This may involve multiple cores within one CPU or multiple CPUs in a single machine . Parallel processing greatly improves performance for tasks that can be divided into smaller sub-tasks , such as simulations and graphics rendering . However, some problems cannot be parallelised because they must be executed sequentially . Q uesto's K ey T erms Instruction Sets: instruction set, complex instruction set computer (CISC) , reduced instruction set computer (RISC) GPUs: graphics processing unit (GPU) Multicore Systems: multicore systems, parallel processing D id Y ou K now? Sony coined the term ' GPU ' for the PlayStation (1994), making it one of the first home consoles with a dedicated graphics processor . The term was later popularised further by NVIDIA in 1999 with the GeForce 256 . 1.1 - The Processor A-Level Topics 1.3 - Input, Output & Storage

Learn about the methods of digital protection including antimalware, firewalls and obfuscation. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification for Unit 2 (Global Information). 6.6 - Logical Protection Exam Board: OCR Specification: 2016 - Unit 2 Logical protection refers to using digital methods of security to protect computer systems and data. Usernames & Passwords ****** Anti-Malware Usernames must be matched with a secure password to minimise the chances of unauthorised users accessing a system. Passwords should contain a mix of uppercase and lowercase letters , punctuation and numbers . Passwords should be of a substantial length (at least 8 characters) and should be regularly changed . Anti-virus software scans a system and removes viruses . If left to infect a system a virus could delete data or permit access to unauthorised users . Anti-spyware software removes spyware on an infected system so hackers cannot view personal data or monitor users. Organisations should install and regularly update anti-virus and anti-spyware programs. Firewall Encryption Firewalls prevent unauthorised access to or from a network . Firewalls filter data packets and block anything that is identified as harmful to the computer system or network. Firewalls can also be used to block access to specific websites and programs. A firewall can be in the form of a physical device which is connected to the network, or software installed on a computer system. Encryption is the conversion of data ( plaintext ) into an unreadable format ( ciphertext ) so it cannot be understood if intercepted . Encrypted data can only be understood by an authorised system with a decryption key . There are two types of encryption . Encryption at rest is when data is encrypted while it is being stored on a system or storage drive. Encryption in transit is to secure the data as it being transferred between systems on a network. Tiered Levels of Access Obfuscation ?????? The purpose of tiered levels of access is to grant different types of permission to certain users. Managing levels of file access ensures that only authorised people can access and change certain files . There are different levels of file access : No access Read-only - Allows a user to view but not edit. Read/write - Allows a user to view and edit. Obfuscation is when data is deliberately changed to be unreadable to humans but still understandable by computers . Program code might be obfuscated to stop rival programmers from viewing and stealing it if they were able to access it. Specialist software can be used to obfuscate data and convert it back into a human-readable format. Q uesto's Q uestions 6.6 - Logical Protection: 1a. Describe why usernames and strong passwords are necessary. [2 ] 1b. State 3 rules for choosing a strong password . [3 ] 2. Describe the purpose of anti-virus and anti-spyware software. [4 ] 3. Describe the roles of a firewall . [4 ] 4. Explain what encryption is. What are the two types? [4 ] 5. Why would an organisation use tiered levels of access ? What are the 3 levels of file access ? [5 ] 6. What is obfuscation ? State a scenario in which it would be used. [3 ] 6.5 - Physical Protection Topic List

Learn about the three factors that affect computer performance - cache memory, clock speed and the number of cores. Based on the J277 OCR GCSE Computer Science specification (first taught from 2020 onwards). 1.2: CPU Performance Exam Board: Cambridge OCR Specification: GCSE - J277 Watch on YouTube : CPU Performance How these CPU characteristics affect the performance of a computer system: Clock speed Cache size Number of cores What You Need to Know Clock Speed A computer has a component called a clock , which produces regular electrical pulses . Clock speed is the number of clock pulses the CPU receives per second . It is measured in gigahertz (GHz ). For example, 3.5 GHz is 3.5 billion pulses per second . The Control Unit (CU ) uses each clock pulse to send control signals that coordinate operations within the computer. A higher clock speed improves the performance of the CPU because more fetch-execute cycles can be completed per second . This means more instructions can be executed in the same amount of time , so tasks can be completed faster . Cache Size Cache memory is fast , temporary storage inside (or very close to) the CPU , which stores frequently accessed data and instructions . It is typically split into three levels (L1 , L2 and L3 ), with each level generally being larger but slower than the previous level. As data and instructions are fetched during the fetch-execute cycle , frequently accessed data and instructions can be stored in cache , reducing the need to repeatedly fetch them from RAM, which is slower to access . A CPU with a larger cache can store more frequently accessed data and instructions , improving performance because they can be accessed faster from cache than from RAM . Number of Cores Some CPUs have multiple cores . A core is an individual processing unit within the CPU , containing components such as a control unit , ALU , registers and cache . Each core can independently perform the fetch-execute cycle . A CPU with more cores can have higher performance because it can process more instructions at the same time . However, performance may not improve if one core must wait for another to complete its task . Also, some software is not designed to use multiple cores , so it will not benefit from having additional cores . Single-core Dual-core Quad-core Octa-core Q uesto's Q uestions 1.2 - CPU Performance: Clock Speed 1a. What is clock speed ? What is it measured in? [ 2 ] 1b. Explain how a higher clock speed improves performance . [ 2 ] Cache Size 2a. What is cache memory ? [ 2 ] 2b. Describe why a larger c ache size may mean performance is higher . [ 4 ] Number of Cores 3a. What is a core ? [ 2 ] 3b. Explain why a quad-core processor should have a higher performance than a dual-core processor . [ 3 ] 3c. Explain two reasons why having more cores doesn't necessarily mean the performance will be better . [ 2 ] 1.1b - Fetch-Execute Cycle 1.3 - Embedded Systems Theory Topics

About CSNewbs Plus (CSN+) CSN+ is a premium collection of resources made for teachers that follows the Computer Science specifications covered on the website . Currently, these resources are in development , with the Eduqas GCSE resource pack arriving first, based on the Eduqas GCSE Computer Science 2020 specification . < Free zip folder download of all resources for Eduqas GCSE topic 1.1 (The CPU) *Updated Jan 2021* Resources included for each topic: Lesson Slides Starter activity (to print) Task resources (e.g. diagrams or worksheets to print) Task answers What is included in the CSNewbs+ GCSE collection? 39 presentation slides 39 starters 39 task answer documents 19 revision activity pages 7 topic tests & answers See below for more details: + Complete presentation slides for each of the 39 theory topics in the Eduqas GCSE 2020 specification . PowerPoint and Google Slides compatible. Activity resources to print . Including diagrams , tables and worksheets for lesson tasks . All answers included for teachers to use. Starter questions that recap the previous topic. For teachers to print before the lesson. All answers included in the lesson slides. 39 starters . Comprehensive answers for all lesson tasks . 39 task answer documents containing answers for over 100 lesson tasks for teachers to use . Revision templates for students to complete, to print on A3 paper . 19 pages and 7 revision lesson slides . Exercise book headings and the driving question (lesson focus) 7 end-of-topic tests with brand new questions . All answers included for teachers. What is included on the presentation slides? The following breakdown shows the presentation slides for 1.1 (The CPU): A title slide The content covered from the Eduqas GCSE specification Exercise book headings and the driving question (lesson focus) Answers to the starter activity questions Lesson objectives An explanation of the topic Clear explanations of the content First task. Students use slides or CSNewbs to complete. All answers on separate teacher document. Task 2. Table provided in teacher resource pack to print. Further explanations of the content Further explanations of the content with diagrams. Further explanations of the content with diagrams. Task 3. Answers in the teacher document. Plenary to check the students' understanding of the lesson topics. < Free zip folder download of all resources for Eduqas GCSE topic 1.1 (The CPU) *Updated Jan 2021*

Learn about laws regarding suitable data disposal of information and computer systems as well as methods including electromagnetic wipe and physical destruction. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification. 5.6 - Data & System Disposal Exam Board: OCR Specification: 2016 - Unit 1 Computer components such as circuit boards, processors and monitors contain hazardous materials that cannot be disposed of in traditional ways such as rubbish collection and landfills. For security reasons, data must also be disposed of carefully so that it is not returned to a readable format by unauthorised viewers . Legislation In recent years, the government has introduced different laws that relate to the safe disposal of computer equipment to help reduce environmental impact . Waste Electronic and Electrical Equipment ( WEEE ) Directive : This provides guidance on how hazardous materials should be disposed of safely . This includes materials such as mercury (found in smartphones and newer monitors ) and toner cartridges in printers . These materials can damage the environment if not disposed of appropriately . Waste Acceptance Criteria ( WAC ): Equipment must meet these rules before it can be sent to a landfill . Hazardous materials, such as the elements in computer monitors , do not meet these criteria and should not be accepted . Hazardous Waste Directive : This ensures businesses safely store hazardous materials and use authorised businesses to dispose of the waste . Hazardous materials include mercury and hexavalent chromium . Data Protection Act ( DPA ): One principle of the DPA specifies that data should only be kept for a reasonable amount of time until it is securely deleted . Data stored on customers should be checked regularly and permanently deleted if no longer required . Methods of Data & System Disposal Overwriting is when new data is written to the hard disk drive to replace the current data - essentially resetting the data . Remember all data stored by a computer is in a binary format . Overwriting just once is usually not enough to remove all evidence of the data and the process may be repeated several times . Overwriting data causes no damage and means the drive can still be used for other purposes afterwards. Electromagnetic wiping uses a machine called a degausser , which has a very strong electromagnetic coil , to completely wipe the hard disk drive . Many large organisations use degaussers to be sure that their data is no longer on the devices they have used so it can’t be restored and accessed by unauthorised viewers . Degaussers are expensive to buy but it allows the device to be used again for other purposes afterwards as it is not physically damaged. A third option is the physical destruction of a computer system or storage device , like a hard disk drive , which guarantees the data is permanently inaccessible . However, physical destruction also renders the storage media unusable again for other purposes. Examples of physical destruction include shredding (e.g. a CD shredder ) or tools such as sledgehammers if no other option is available. Q uesto's Q uestions 5.6 - Data & System Disposal: 1. Describe the purpose of 4 different pieces of legislation relating to how data or computer systems should be disposed of safely . [8 ] 2a. State 3 methods of data and system disposal . [3 ] 2b. Describe 1 advantage and 1 disadvantage of using each method you stated in 2a. [6 ] 5.5 - Digital Security Topic List

Learn about input and output devices used with computer systems. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification. 1.1 - Computer Hardware Exam Board: OCR Specification: 2016 - Unit 1 Input Devices An input device allows data, such as text, images, video or sound, to be entered into a computer system. Common input devices: Mouse Keyboard Scanner Controller Microphone Webcam Chip Reader OCR / OMR Scanner Barcode Scanner Graphics Tablet Sensors (e.g. light or temperature) Touch Screen Remote Control Biometric Scanner (e.g. fingerprint or iris) Concept Keyboard Output Devices There are many outputs created by a computer system, including printed documents, on-screen data and sound. Common output devices: Monitor Printer (e.g. inkjet or laser) Plotter Speakers Projector Alarm Light Headphones Touch Screen Braille Terminal Communication devices can be found in 1.5 . Biometric Devices A biometric device uses a human characteristic as part of its security mechanism, such as a fingerprint , iris (eye), face o r voice . Organisations using biometrics must instruct each employee to first input their information to a database , by scanning their fingerprint for example. Whenever the scanner scans a finger it searches in its database to see if the fingerprint matches one that it already holds . Only authorised employees will have already scanned their fingerprints so if there is no match then access is not allowed . Advantages of biometric devices: Security is improved as biometrics can't be shared like passwords can. Even if a password is exposed the system can't be accessed without having the biometric too. Biometric scanners verify that a user is who they claim to be. Using a biometric device (e.g. fingerprint scanner) might be quicker and easier than entering a username and password. Disadvantages of biometric devices: Can be expensive to install and all users must take the time to initially set up by entering their biometric into the database so they will be recognised by the system. Unreliable in that it can be affected by the environment (e.g. dirty fingers can't be used with a fingerprint scanner or voice recognition may not work in a loud environment). Disabled users might not be able to provide the biometric required. Privacy concerns - users might not want their personal characteristics stored on a computer system. Q uesto's Q uestions 1.1 - Computer Hardware: 1. Make a list of 5 input devices and 5 output devices . Challenge yourself to look up and include devices from this page you may not be familiar with. [10 ] 2a. State 3 human features that may be recorded by a biometric device . [3 ] 2b. Describe how a biometric device works . [3 ] 2c. A school is considering installing biometric devices to allow only sixth form students to enter certain parts of the school. Describe 3 advantages and 3 disadvantages to the school of using biometrics in this way. [10 ] Topic List 1.2 - Computer Components

Learn about different types of hardware that allow data to be sent between systems, including router, modem, bridge and WAP. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification. 1.5: Communication Hardware Exam Board: OCR Specification: 2016 - Unit 1 The devices on this page are used to create or link together networks , allowing data to be sent between computer systems . Hub A hub receives data packets from a connected device and transfers a copy to all connected nodes . Switch A switch receives data packets , processes them and transfers them on to the device s pecifically listed in the destination address of the packet. Modem Modems are used to send data across the telephone network . The telephone lines can only transfer analog signals so a modem is used to convert a computer's digital data into an analog signal . Another modem converts the signal back to a digital format at the receiving end. Router Routers are used to transfer data packets between networks . Data is sent from network to network on the internet towards the destination address listed in the data packet. A router stores the address of each computer on the network and uses routing tables to calculate the quickest and shortest path . Wireless Access Point (WAP) Provides a link between wireless and wired networks . It creates a wireless local area network that allows WiFi enabled devices to connect to a wired network. Combined Device Also known as a hybrid device , this provides the functionality of multiple communication devices (e.g modem, router, switch and/or wireless access point) in a single device . They can be more expensive than a single device but are more adaptable - if the routing part of the device fails it might still be able to function as a switch / wireless access point etc. However, you will see an increased performance from a standalone device rather than a combined one as standalone devices have more complex features (e.g. VPN support). Network Interface Card (Network Adapter) A Network Interface Card (often shorted to NIC ) is an internal piece of hardware that is required for the computer to connect to a network . It used to be a separate expansion card but now it is commonly built directly into the motherboard (and known as a network adapter ). Wireless network interface cards allow wireless network connection. Q uesto's Q uestions 1.5 - Communication Hardware: 1. What is the difference between a hub and a switch ? [2 ] 2. Explain how a modem works. [3 ] 3. Explain the purpose of a router . [2 ] 4. What is a Wireless Access Point (WAP )? [2 ] 5. Describe what is meant by a 'combined device '. Give one advantage and one disadvantage of using a combined device. [3 ] 1.4 - Connectivity 1.6 - Hardware Troubleshooting Topic List

Learn about common prevention methods of minimising cyber security risks including anti0malware, firewalls and penetration testing. Based on the J277 OCR GCSE Computer Science specification (first taught from 2020 onwards). 4.2: Preventing Vulnerabilities Exam Board: OCR Specification: J277 Watch on YouTube : Preventing Vulnerabilities Penetration Tests Penetration tests are carried out as part of ethical hacking. The purpose of a penetration test is to review the system's security to find any risks or weaknesses and to fix them . Internal tests are to see how much damage could be done by somebody within the company with a registered account. External tests are for white hat hackers to try and infiltrate a system from outside the company . Anti-Malware Software Anti-malware software is used to locate and delete malware, like viruses, on a computer system. The software scans each file on the computer and compares it against a database of known malware . Files with similar features to malware in the database are identified and deleted . There are thousands of known malware, but new forms are created each day by attackers, so anti-malware software must be regularly updated to keep systems secure. Other roles of anti-malware software: Checking all incoming and outgoing emails and their attachments . Checking files as they are downloaded . Scanning the hard drive for viruses and deleting them . Firewall A firewall manages incoming and outgoing network traffic . Each data packet is processed to check whether it should be given access to the network by examining the source and destination address . Unexpected data packets will be filtered out and not accepted to the network. Other roles of a firewall include: Blocking access to insecure / malicious web sites . Blocking certain programs from accessing the internet . Blocking unexpected / unauthorised downloads . Preventing specific users on a network accessing certain files . Secure Passwords ******** Usernames must be matched with a secure password to minimise the chances of unauthorised users accessing a system. Passwords should contain a mix of uppercase and lowercase letters , punctuation and numbers . Passwords should be of a substantial length (at least 8 characters) and should be regularly changed . User Access Levels Access levels are used to only allow certain users to access and edit particular files. ' Read-Only ' access is when a user can only view a file and is not allowed to change any data . For example, a teacher might set homework instructions as read-only for students to view. ' Read and Write ' access allows a user to read and edit the data in a file. For example, a teacher might set an online workbook as read and write access for students to fill in. It is important to set access levels so that only authorised users can view and change data. The more users who have access to a file, the more likely it is to be compromised. Certain users may also have no access to a file - when they can't view or edit it. Encryption Encryption is the process of scrambling data into an unreadable format so that attackers cannot understand it if intercepted during transmission. The original data (known as plaintext ) is converted to scrambled ciphertext using an encryption key . Only at the correct destination will the encryption key be used to convert the ciphertext back into plaintext to be understood by the receiving computer. Physical Security A lock can be used to prevent access to server rooms or locations that store confidential data . Only authorised personnel with a matching key will have access. Biometric devices require the input of a human characteristic (such a fingerprint , iris or voice ). The biometric data is checked against previously inputted data in a database. Only a match will allow access to the user. Other forms of physical security include keycards , security staff , CCTV cameras and alarms . Q uesto's Q uestions 4.2 - Preventing Vulnerabilities: 1. Describe the purpose of penetration tests . [2 ] 2. Describe the purpose of anti-malware software and its different roles . [ 4 ] 3. Describe the purpose of a firewall and its different roles . [ 4 ] 4. State three rules for choosing a strong password . [ 3 ] 5. Describe the three types of access level . [6 ] 6a. Describe the purpose of encryption . [ 2 ] 6b. Explain how encryption works, using the terms plaintext , key and ciphertext . [ 4 ] 4.1 - Security Threats Theory Topics 5.1 - Operating Systems