Year 9 Computing Mid-Term Revision Guide PDF

Year 9 Computing Mid-Term Revision Guide Hardware and Software Basics Key Concepts: ◦ Internal Hardware: ◦ Components located inside a computer, such as the Central Processing Unit (CPU), Graphics Processing Unit (GP...

Year 9 Computing Mid-Term Revision Guide Hardware and Software Basics Key Concepts: ◦ Internal Hardware: ◦ Components located inside a computer, such as the Central Processing Unit (CPU), Graphics Processing Unit (GPU), Random Access Memory (RAM), and motherboard, Read Only Memory (ROM) ◦ Central Processing Unit (CPU): The main processor that performs calculations, logic, and controls most tasks in a computer. ◦ Graphics Processing Unit (GPU): A specialized processor designed to handle rendering images, videos, and animations for display. ◦ External Hardware: ◦ Devices connected externally to a computer, like a keyboard, mouse, printer, speaker, microphone, headphones and monitor. Table 1: Hardware Examples Type Examples CPU, RAM, Hard Disk Drive (HDD), ROM, GPU, Internal Hardware Motherboard Mouse, Printer, Monitor, Keyboard, Microphone, Speaker, External Hardware Headphones Software: ◦ System Software: Manages hardware and provides a platform for application software (e.g., Operating Systems, Utility Software like Compilers, Device Drivers and Backup Tools). ◦ Application Software: Designed for end-users to perform speci c tasks (e.g., Word Processors, Web Browsers, etc.). Table 2: Software Examples Type Examples Operating System (Windows, macOS), Device Drivers, Utilities System Software (Compilers, Backup, Compression) Application Word Processors, Spreadsheets, Presentation Software, Image Editing Software Software, Video Editing Software, Database Management Software 1  fi  2. Types of Computers Key Concepts: ◦ Desktop Computers: Traditional PCs, often used for work and gaming, with higher performance but limited portability. ◦ Laptops: Portable computers with built-in screens, keyboards, and batteries. ◦ Tablets: Lightweight and touchscreen-based, primarily used for media consumption and light computing tasks. ◦ Supercomputers: High-powered machines used for complex calculations, simulations, and data processing. ◦ Servers: Dedicated computers that provide services to other computers on a network. Table 3: Computer Types Comparison Computer Characteristics Example Use Cases Type Desktop High performance, less portable Gaming, of ce work Laptop Portable, moderate power Education, business trips Tablet Lightweight, touchscreen Media consumption, note-taking High computing power, very Climate modeling, scienti c Supercomputer expensive research Hosting websites, data Server Manages network resources management 3. Operating Systems (OS) Key Concepts: ◦ OS provides an interface between hardware and users, managing resources and applications. ◦ Examples include Windows, macOS, Linux. 4. User Interfaces (UI) Types of User Interfaces: ◦ Graphical User Interface (GUI): Interaction through icons, buttons, and menus (e.g., Windows, MacOS, iOS). ◦ Command Line Interface (CLI): Text-based interface where users input commands (e.g., Linux Terminal). ◦ Voice User Interface (VUI): Users interact using spoken commands (e.g., Amazon Alexa, Google Assistant, Siri). ◦ Gesture-Based Interface: Interacting using physical gestures (e.g., gaming consoles like the Nintendo Wii). 2  fi fi  Table 4: User Interface Comparison Type Bene ts Drawbacks User-friendly, visual GUI More resource-intensive navigation CLI Fast for experts, ef cient Steeper learning curve Hands-free, intuitive Requires speech recognition VUI interaction accuracy Gesture- Engaging, immersive May require speci c hardware Based Networking and Telecommunications Networking Concepts IP Address and Domain Name: ◦ IP Address: A unique number that identi es a device on a network (e.g., 192.168.1.1). ◦ Domain Name: A human-friendly name for websites (e.g., google.com). ◦ DNS (Domain Name System): Translates domain names to IP addresses. LAN (Local Area Network): ◦ A network that covers a small area, like a home, of ce, or school. ◦ Connects devices close together, providing fast data transfer. WAN (Wide Area Network): ◦ A network that covers a large geographical area, connecting multiple LANs. Examples include the internet. ◦ Useful for connecting devices over long distances. WLAN (Wireless Local Area Network): ◦ A type of LAN that uses wireless technology (e.g., Wi-Fi) to connect devices. ◦ Allows for mobility within a local area without needing cables. Network Devices Router: ◦ Connects different networks, like your home network to the internet. ◦ Directs data packets between networks, often providing Wi-Fi access at home. Modem: ◦ Known as Modulator Demodulator ◦ Converts digital data from a computer into a format suitable for transmission over different types of connections, like telephone lines (DSL) or cable. ◦ Often works alongside a router for internet access. 3  fi fi fi fi fi  Bridge: ◦ Connects two separate networks, making them function as a single network. ◦ Useful for splitting or combining network traf c. Hub: ◦ A basic network device that connects multiple devices. It broadcasts data to all connected devices, regardless of the intended recipient. ◦ Less intelligent than switches and often considered outdated for modern networks. Switch: ◦ Connects multiple devices within a LAN. Unlike hubs, switches direct data only to the intended recipient device, making it more ef cient. ◦ Used in most modern local networks to manage data ow. NIC (Network Interface Card): ◦ A hardware component that allows a computer or device to connect to a network. It can be built-in or added separately. ◦ Provides a unique MAC address for network identi cation. Telecommunications and Wireless Technologies Bluetooth: ◦ Short-range wireless technology used for connecting devices like headphones, keyboards, and phones within a few meters. ◦ Great for transferring small amounts of data or for personal area networks (PANs). Wi-Fi: ◦ Wireless networking technology used to connect devices to the internet or to each other within a LAN. ◦ Offers longer range than Bluetooth and is common for home and public internet connections. RFID (Radio-Frequency Identi cation): ◦ Uses radio waves to identify and track tags attached to objects. Commonly used in inventory tracking, security tags, and toll payments. ◦ NFC is a speci c type of RFID that works at very short ranges and is typically used for secure data exchange. NFC (Near Field Communication): ◦ A type of RFID technology that allows for close-range communication (usually a few centimeters). ◦ Often used for contactless payments (e.g., tapping a phone or card on a payment terminal). 4  fi fi fi fi fi fl  UWB (Ultra-Wideband): ◦ Wireless communication technology that allows for precise location tracking and fast data transfer over short distances. ◦ Often used for indoor location tracking and smart home devices. 4G: ◦ Fourth-generation mobile network technology used for faster internet speeds on mobile devices. ◦ Commonly used for mobile browsing, streaming, and app usage. 5G (Fifth Generation): ◦ The latest generation of mobile network technology, providing much faster speeds and lower latency than 4G. ◦ 5G Sub-6 GHz: Provides good coverage over longer distances but with slightly lower speeds than mmWave. ◦ 5G mmWave (Millimeter Wave): Offers extremely fast speeds and low latency but works over shorter distances and struggles with obstacles like walls. Summary Table of Networking Devices and Technologies Device/ Description Technology Router Connects different networks; often provides internet access. Modem Converts digital data for transmission over various networks. Bridge Connects two separate networks to act as one. Hub Connects devices in a network by broadcasting data to all devices. Connects devices in a network by directing data only to the intended Switch recipient. NIC Allows a device to connect to a network; provides a unique MAC address. Bluetooth Short-range wireless communication for connecting personal devices. Wi-Fi Wireless networking for connecting to the internet or LANs. NFC Short-range communication for secure data exchange (contactless payments). RFID Uses radio waves for tracking and identifying objects. UWB Used for precise location tracking and fast data transfers. 4G Mobile network technology for fast internet access. 5G Sub-6 GHz 5G technology with good coverage and faster speeds than 4G. 5G mmWave Ultra-fast speeds but shorter range and limited penetration. 5   Cybersecurity Passwords ◦ Weak Passwords: Simple, easily guessed passwords (e.g., "password123"). ◦ Strong Passwords: At least 10 characters, including a mix of uppercase, lowercase, symbols, and numbers. Why Password Reuse is a Risk: ◦ If one site is breached, attackers can access multiple accounts. ◦ Password Managers: Securely store, manage and generate unique passwords for each service, and also inform if the user’s password has been in a data breach so action can be taken by the user. Table 6: Password Characteristics Strength Level Characteristics Example Weak Common words, simple numbers 123456, password Long, mixed case letters, numbers, symbols, no Strong M@ssP0rd!45 common words Social Engineering and Phishing Key Concepts: ◦ Social Engineering: Psychological manipulation to trick individuals into divulging con dential information. Tactics include impersonation, pretexting, and baiting. ◦ Phishing: A form of social engineering where attackers impersonate trusted entities (e.g., banks, companies) to steal data. Phishing Examples: ◦ Email Phishing: Fraudulent emails requesting sensitive information. ◦ Spear Phishing: Targeted attacks on speci c individuals using personalized details. ◦ Vishing (Voice Phishing): Phone calls used to trick individuals into revealing sensitive information. ◦ Smishing (SMS Phishing): Text messages used for phishing attempts. Public Wi-Fi can be insecure, exposing users to data interception. ◦ Protection Measures: ▪ VPN: Encrypts data by establishing encrypted connections between devices and hides online activity and location. ▪ Avoid Sensitive Transactions: Do not access banking services or make credit card transactions. Table 5: Social Engineering Tactics Technique Description Impersonation Pretending to be someone else to gain trust Pretexting Creating a fabricated scenario to extract information Phishing Using fake communication to steal sensitive data 6  fi fi  How you can protect your personal data online, especially when browsing the web: 1. Use Strong Passwords: ◦ Make sure your passwords are long and include a mix of case sensitive letters, numbers, and symbols. Avoid using easy-to-guess passwords like "123456" or "password". 2. Enable Multi-Factor Authentication (MFA) or Two-Factor Authentication (2FA(: ◦ This adds an extra layer of security by requiring a second form of identi cation in addition to a password, like a text code, an app con rmation or biometric veri cation like ngerprint. Bene ts of this include: ◦ Enhanced Security: Even if one factor (e.g., your password) is compromised, a second factor is still needed, making it much harder for attackers to gain access. ◦ Reduces Risk of Unauthorized Access: Provides a safeguard against phishing attacks, as attackers would need both factors to access your account. 3. Watch for "HTTPS" in Website URLs: ◦ When browsing websites, make sure the URL starts with https:// instead of just http://. The "s" stands for "secure" and means your data is encrypted and safer from being stolen. 4. Be Careful on Public Wi-Fi: ◦ Public Wi-Fi networks can be risky because others may try to steal your data. Use a Virtual Private Network (VPN) or avoid sharing personal information on public Wi-Fi. 5. Keep Your Software Updated: ◦ Make sure your computer, phone, and apps have the latest security updates to protect against new threats. 6. Think Before You Click: ◦ Be cautious of clicking on links or downloading les from unknown emails or messages. These can be phishing scams trying to steal your information. 7. Use Antivirus Software: ◦ Install antivirus software and keep it updated to protect against viruses, malware, and other threats. 8. Limit the Personal Information You Share: ◦ Be careful about sharing personal details online, especially on social media or public websites. 9. Use Secure Password Managers: ◦ Password managers store and create strong passwords for you, so you don’t have to remember each one. 7 fi  fi fi fi fi fi  Hypertext Markup Language (HTML) Tags: Used to create elements (e.g., , , ): 1. : ◦This line tells the computer that we're using the latest version of HTML. It helps the web page display correctly. 2. : ◦This is the main container for all the HTML code. Everything you put in your webpage goes between the and tags. 3. : ◦The head section holds information about the page, like its title and some instructions. It's not something you see on the webpage itself. 4. : ◦This sets the name of the web page. It shows up on the tab at the top of your web browser. 5. : ◦ This is where all the stuff you want people to see on your webpage goes, like text, pictures, and lists. 6. : ◦ This is used to make the biggest heading or title on your page. Think of it like a big, bold title for a section. 7. : ◦ This tag is for paragraphs of text. It’s used when you want to write sentences or a block of text. 8. (Unordered List): ◦ This tag makes a list of items with bullet points. You use it when the order of items doesn’t matter. ◦ (List Item): Each item in the list goes inside an tag. 9. (Ordered List): ◦ This creates a list with numbers. You use it when you want the items to be in a speci c order. ◦ (List Item): Each item in the list goes inside an tag. 10. : ◦ This tag puts an image on your webpage. ◦ src (source) tells the computer where to nd the image. ◦ alt is text that shows up if the image can't load or if someone can’t see it. 8  fi fi  Most HTML tags have a start tag and an end tag. For example:..................... (list)... (list item)... (ordered list) You always need to close these tags with. The closing tag has a / before the tag name. Tags that do NOT need closing: ◦ Some tags don’t need a separate closing tag. They are self-closing tags. ◦ Examples: ▪ : Used to add an image. It doesn’t need a closing tag. It looks like this:. ◦ In these tags, you do not need a separate closing like. HTML Structure (Example Webpage:) ◦ ◦ ◦ ◦ My Life ◦ ◦ ◦ About Me ◦ Hello, I am a student who enjoys several activities: ◦ ◦ Reading ◦ Gaming ◦ Sports ◦ ◦ These are some games I play: ◦ ◦ Fortnite ◦ Roblox ◦ Deadlock ◦ ◦