Fundamentals of Computer Networks- CompSci AQA GCSE

• Network


  Two or more computers - or other electronic devices - that are connected together for the purpose of communication
• Stand-alone


  A computer or device that is not connected to a network
• Devices that can be connected to a network

  • PCs
  • Smartphones
  • Smartwatches
  • Fitness trackers
  • Car engine management systems
  • Internet-enabled fridges
  • Intelligent personal assistants
  • Media boxes
• Types of network


  • Local area networks (LANs)
  • Wide area networks (WANs)
  • Personal area networks (PANs)
• LAN


  • Geographically confined to one building or site
  • Owned and maintained by the organisation
• WAN


  • Spread over a wide geographical area
  • Covers more than one site, or be spread across a country, or even the world
  • Communication is through national telephone infrastructures or via wireless transmission
• PAN


  • Spread over a very small area, often no more than a few metres
  • Used to connect personal devices such as a smartphone and wireless headphones or a laptop
• Network types


  • Wired networks
  • Wireless networks
• Wired networks


  Use physical wiring to connect devices
• Wireless networks


  Use radio waves to carry signals
• Local area network hardware

  • Network interface controller (NIC) or wireless network interface controller
  • Transmission medium, either wired or wireless
  • Point to connect to, such as a router, hub, switch or wireless access point (WAP)
• Network interface card (NIC)


  • Offers an interface port for a wired connection
  • Wireless NIC provides a radio transceiver for connecting wirelessly
• Network connection devices


  • Switches
  • Routers
• Switches


  • Record which computers are connected to which ports
  • Forward traffic to its intended recipient only, improving network performance
• Routers


  • Used to send data signals across the internet
  • Collect knowledge of available routes to transmit data and determine the most suitable route
  • Commonly used in homes, containing additional hardware to form a network and a modem to connect to the internet
• Wired transmission media


  • Twisted copper wiring
  • Fibre-optic cable
• Wireless access point (WAP)

  • Uses a radio transceiver to allow wireless connections to a network
  • Creates its own wireless network which devices connect to
  • Can be used to extend the range of a wireless network
• Advantages of using networks

  • File sharing
  • Hardware sharing
  • Communication
  • Roaming access
  • Centralised maintenance and updates
  • Centralised security
  • User monitoring
  • Levels of access
• Disadvantages of networks


  • Cost
  • Management
  • Spread of malware
  • Hacking