11.6.1.1 compare features of local (LAN) and wide area networks (WAN)

Computer network

A computer network is a number of computers linked together to allow them to share resources (hardware, software and data).

Advantages of using computer network:

• The ability to share devices such as printers. This feature saves money.
  Files can be easily shared between users.
  Security and Privacy - Users cannot see other users' files on the same workstation.
  If all data is stored on a server on the network, then it is easy to back up the data.

Disadvantages of using computer network:

• Buying network cables and file servers can be costly.
  A system administrator is required to manage the network.
  If the server goes down, the files become inaccessible.
  Viruses can spread to other computers on a computer network.
  Hacking danger. You need to use additional security software such as a firewall.

LAN and WAN

Local Area Network (LAN) - devices connected together usually within the same room or building.

For example, a school or an office complex network.

Wide Area Network (WAN) - devices connected together over a large geographical area (global). WANs can be connected together using the Internet, leased lines or satellite links.

For example, the Internet or a network of bank cash dispensers.

LANs are often connected to WANs, for example, a school network could be connected to the Internet.

Next topic "Network topology"

Questions:

Exercises:

Ex. 1

Ex. 2

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