Networks: LAN and WAN

Networks: LAN and WAN

Networks

  • A network is a group of computer systems linked together. They may be linked by wired connections such as Ethernet cables, or wireless connections such as Wi-Fi or Bluetooth.
  • Networks allow computers to share resources, such as files and printers, and to communicate with each other.

Local Area Network (LAN)

  • A Local Area Network (LAN) is a network covering a small, localised area, such as a home, office, or school.
  • LANs are usually owned and managed by a single organisation or individual.
  • LANs can be wired (using Ethernet cables) or wireless (using Wi-Fi).
  • Devices which make up a LAN are usually close together, often in the same building.

Wide Area Network (WAN)

  • A Wide Area Network (WAN) covers a larger geographical area, often spanning cities or countries.
  • WANs are typically made up of multiple LANs connected together.
  • WANs are often owned and maintained by multiple organisations or service providers.
  • The internet is the largest example of a WAN, connecting networks all over the globe.

Network Protocols

  • Network protocols are sets of rules defining how devices on a network communicate and interact with each other.
  • Some common protocols include HTTP (for web browsing), FTP (for file transfer), and SMTP (for email).

Wireless Networks

  • Wireless networks use radio waves to transmit data between devices.
  • They provide mobility and freedom from wires, but they can be less secure and more prone to interference than wired networks.
  • Crucial for mobile device connectivity.

Network Security

  • Networks, especially those connected to the internet, can be vulnerable to attacks, including hacking and viruses.
  • Network security measures include firewalls, encryption, and secure password practices.
  • Firewalls control traffic entering and leaving the network, blocking unauthorised access.
  • Encryption converts data into a code to prevent unauthorised access.

Data Transmission

  • Networks can use different methods to transmit data, these include serial, parallel, simplex, half-duplex, and full-duplex transmission.
  • Understanding these transmission types is key to understanding network data flow.

Network Topologies

  • The physical layout or arrangement of a network is referred to as its topology.
  • Common topologies include Bus, Ring, Star and Mesh, each with their own advantages and disadvantages.