Year 9 ICT Revision Booklet PDF

Here's a structured markdown conversion of the provided text from the images: # Year 9 ICT End of Term 2 Revision Booklet **Exam Details** - Duration: 60 Minutes - Topics Covered: Term 2 Network and Data Transmission concepts + Binary, Denary, and Hexadecimal Conversion from Term 1 **Revision Top...

Here's a structured markdown conversion of the provided text from the images: # Year 9 ICT End of Term 2 Revision Booklet **Exam Details** - Duration: 60 Minutes - Topics Covered: Term 2 Network and Data Transmission concepts + Binary, Denary, and Hexadecimal Conversion from Term 1 **Revision Topics** ## 1. Introduction to Networks - What is a computer network? a computer network is a system that connects two or more computing devices for transmitting and sharing information - Why do we need networks? Allows computers to share and access resources and provides access to information and data - Are networks safe? because of the widespread use of encryption, connecting through public wi-fi is usually safe, but you can still get hacked, whereas private networks are more controlled and secure - Dangers of sharing data over networks - Malware infection - Hacking - Data loss ## 2. Network Hardware - Devices: Switch - equipment that allows 2 or more devices, such as computers to communicate with each other. - Hub - a device that links many computers and devices together. - Router - device that connects 2 or more packet-switched networks and it connects any device to a network. - Network Interface Card (NIC) - a circuit board installed in a computer to allow it to be connected to a network **Wired vs. Wireless: Advantages and disadvantages** ### Wired Connections (Ethernet, HDMI, USB, etc.) **Advantages** - Faster Speeds – Generally offer higher data transfer rates and lower latency. - More Reliable – Less interference and signal degradation compared to wireless. - Better Security – Harder to intercept data compared to wireless signals. - Consistent Performance – No dropouts or fluctuations due to interference. **Disadvantages** - Limited Mobility – Devices must stay connected via cables. - Clutter & Installation – Requires physical cables, which can be messy and harder to set up. - Less Flexibility – Devices are tethered to specific locations. ### Wireless Connections (Wi-Fi, Bluetooth, Cellular, etc.) **Advantages** - Convenience & Mobility – No cables, allowing freedom to move around. - Easier Setup – No need for physical wiring, reducing installation hassle. - Scalability – Easily add more devices without additional infrastructure. **Disadvantages** - Slower Speeds – Wireless is generally slower than wired connections. - Interference Issues – Signals can be affected by walls, other devices, and network congestion. - Security Risks – More vulnerable to hacking and unauthorized access. - Battery Drain – Wireless devices (e.g., Bluetooth, Wi-Fi) consume more power. **Final Thoughts** - Choose wired for high-speed, stable, and secure connections (e.g., gaming, video editing, business networks). - Choose wireless for convenience, flexibility, and mobility (e.g., smartphones, smart home devices, casual browsing). - Network Protocols ## 3. Types of Networks - LAN, WAN, WLAN – Characteristics and Differences **LAN vs. WAN vs. WLAN – Characteristics & Differences** | Feature | LAN (Local Area Network) | WAN (Wide Area Network) | WLAN (Wireless Local Area Network) | |-----------------|--------------------------------------------------------|------------------------------------------------------|------------------------------------------------------| | Coverage Area | Small (single building, office, school) | Large (cities, countries, global) | Small to medium (home, office, campus) | | Technology Used | Ethernet cables, fiber optics, switches | Fiber optics, satellites, leased lines | Wi-Fi (radio signals) | | Speed | High ($1$ Gbps to $10$ Gbps) | Lower than LAN (varies with provider) | Moderate (up to $1$ Gbps with Wi-Fi $6$) | | Security | More secure (private network) | Less secure (more exposure to cyber threats) | Less secure than wired LAN (vulnerable to hacking) | | Cost | Low (affordable setup) | High (requires expensive infrastructure) | Moderate (cost of routers, APs, security) | | Examples | Office network, home network, school network | The internet, corporate networks, banking networks | Home Wi-Fi, public hotspots, airport Wi-Fi | **Key Differences** - LAN: Small, wired network with high speed and security. - WAN: Large-scale network connecting multiple LANs across long distances. - WLAN: A wireless version of LAN, using Wi-Fi instead of cables. ## 4. Network Topologies - Types: Star, Ring, Bus, Mesh - Characteristics of each topology - **Star:** - Central hub connects all devices. - Reliable (failure of one device doesn't affect others) - Single point of failure (if the hub fails, the network goes down) - **Ring:** - Devices connected in a circular path. - Data flows in one direction (or both in dual ring) - Failure in one node can break the network - **Bus:** - Single central cable (backbone) connects all devices. - Easy and cost-effective - Network crashes if backbone fails - **Mesh:** - Every device is interconnected. - Highly reliable (redundancy & no single point of failure) - Expensive & complex setup ## 5. Data Transmission - What is a data packet? data packets are individual information organized into one packet sent through a network path. - Structure of a data packet: - Header - A packet header is a "label" of sorts, which provides information about the packet' - Payload - the actual data being transported by the packet. - Trailer - supplemental data (metadata) placed at the end of a block of data being stored or transmitted - Understanding packet switching ## 6. Cybersecurity - Importance of protecting personal data - if personal data falls into the wrong hands, people could be harmed. Depending on the situation, they could become victims of identity theft, discrimination or even physical harm. - What do hackers do with stolen data? - Hackers seek out personal data that can be used for financial fraud, identity theft, or resold for profit - Difference between data and information - Data comprises raw, unprocessed facts that need context to become useful, while information is data that has been processed, organized, and interpreted to add meaning and value. - What is social engineering? - Social engineering uses psychological manipulation to trick users into making security mistakes or giving away sensitive information 1. What is the main function of a router in a network? - a) Store data permanently - b) Manage network security - c) Direct data packets between networks - d) Convert data into binary 2. Which network topology connects all devices to a central hub or switch? - a) Ring - b) Mesh - c) Bus - d) Star 3. What does the payload of a data packet contain? - a) Sender's IP address - b) Error-checking data - c) Actual transmitted data - d) Encryption keys 4. What is the purpose of a firewall in cybersecurity? - a) Increase network speed - b) Prevent unauthorised access - c) Store encrypted passwords - d) Convert hexadecimal to binary 5. Which network type is best suited for a single building? - a) WAN - b) LAN - c) WLAN - d) Mesh 6. Explain the difference between a LAN and a WAN. (2 Marks) - LAN means local area network. WAN means wide area network. LANs connect users and applications in close geographical proximity (same building). WANs connect users and applications in geographically dispersed locations (across the globe). 7. List two advantages and two disadvantages of wireless networks. (4 Marks) **Advantages** - Convenience & Mobility – No cables, allowing freedom to move around. - Easier Setup – No need for physical wiring, reducing installation hassle. - Scalability - Easily add more devices without additional infrastructure. **Disadvantages** - Slower Speeds – Wireless is generally slower than wired connections. - Interference Issues – Signals can be affected by walls, other devices, and network congestion. - Security Risks – More vulnerable to hacking and unauthorized access. - Battery Drain – Wireless devices (e.g., Bluetooth, Wi-Fi) consume more power. 8. Define packet switching and explain why it is important in networks. (3 Marks) - Packet switching is a technique used in computer networks to transmit data as packets. 9. What is a Network Interface Card (NIC) used for? (2 Marks) - A NIC provides a computer with a dedicated, full-time connection to a network. 10. Explain what happens when a data packet is transmitted over a network. (3 Marks) - it is first broken up into smaller packets, which are then translated into bits. The packets get routed to their destination by various networking devices such as routers and switches. ## Section C: Diagram-Based Questions 11. Draw and label the structure of a data packet. (4 Marks) 12. Below is an incomplete star topology diagram. Complete the missing connections. (3 Marks) 13. Sketch and label a bus topology. Explain one advantage and one disadvantage of using this topology. (5 Marks) ## Section D: Binary, Denary, and Hexadecimal Conversion Questions 14. Convert 1101 0110 (binary) to denary. 15. Convert 248 (denary) to hexadecimal. 16. Convert 3F (hexadecimal) to binary. 17. Convert 10110101 (binary) to denary. 18. Convert 179 (denary) to hexadecimal. 19. Convert 7A (hexadecimal) to binary. ## Section E: Extended Response Questions 20. Describe the risks of social engineering in cybersecurity and suggest three ways to protect against it. (6 Marks) 21. Compare and contrast the bus and mesh network topologies. Include two advantages and disadvantages for each. (8 Marks) 22. Explain the role of network protocols in communication. Provide two examples. (5 Marks) 23. Discuss the importance of packet switching in modern networks. Why is it better than circuit switching? (6 Marks) 24. A company needs to choose between LAN and WAN for its operations. Suggest which one they should use and justify your answer. (5 Marks) 25. Explain how packet switching improves network efficiency compared to circuit switching. (6 Marks)