Networks - OCR A-Level Computer Science

1.3.3 Networks

This section covers the essential concepts of networks in the context of A-Level Computer Science. The notes are designed to aid understanding of network types, components, and functionality.

Key Topics Covered:

• Network Types

  • Local Area Network (LAN)
    • Small geographical area
    • Used in small businesses or homes
  • Wide Area Network (WAN)
    • Large geographical area
    • Connects multiple LANs

• Network Topologies

  • Star Topology
    • Central hub - each device connected directly
    • Advantages: Easy to add new devices, failure of one device doesn't affect others
  • Bus Topology
    • Single central cable (bus) - all devices connected
    • Disadvantages: Difficult to identify issues, failure of central bus affects whole network

• Network Protocols

  • TCP/IP
    • Transmission Control Protocol/Internet Protocol
    • Core protocols of the internet
  • HTTP/HTTPS
    • HyperText Transfer Protocol (Secure)
    • Used for transmitting web pages

• Network Hardware

  • Router
    • Directs data across networks
    • Connects different networks
  • Switch
    • Connects devices within the same network
    • Manages data packets
  • Modem
    • Modulates and demodulates signals for transmission

• Network Security

  • Firewalls
    • Monitor and control incoming and outgoing traffic
    • Create a barrier between trusted and untrusted networks
  • Encryption
    • Converts data into a secure format
    • Ensures data confidentiality

• Network Standards

  • Importance of standardized protocols for interoperability
  • Examples include IEEE 802.11 (Wi-Fi) standards

These notes provide a comprehensive overview of the fundamental concepts of networks essential for A-Level Computer Science students, focusing on the structure, operation, and security of networks.