Local Area Network (LAN)
Often a LAN is a private network belonging to an organisation or business.
Because LANs are geographically small, they usually use cables or low-power radio (wireless) for the connections.
Wireless Local Area Network (WLAN)
At the centre of the WLAN is a wireless switch or router - a small box with one or two antennas sticking out the back - used for sending and receiving data to the computers. (Most laptops have a wireless antenna built into the case.)
It is much more convenient to use wireless connections instead of running long wires all over a building.
Wide Area Network (WAN)
A WAN is often created by joining several LANs together, such as when a business that has offices in different countries links the office LANs together.
Because WANs are often geographically spread over large areas and links between computers are over long distances, they often use quite exotic connections technologies: optical fibre (glass) cables, satellite radio links, microwave radio links, etc.
Bluetooth (Personal Area Network)
The idea of Bluetooth is to get rid of the need for all of those cables (e.g. USB cables) that connect our computer to peripheral devices such as printers, mice, keyboards, etc.
Bluetooth devices contain small, low-power radio transmitters and receivers. When devices are in range of other Bluetooth devices, they detect each other and can be 'paired' (connected)
- Connecting a wireless keyboard to a computer
- Connecting a wireless mouse to a computer
- Using a wireless headset with a mobile phone
- Printing wirelessly from a computer or PDA
- Transferring data / music from a computer to an MP3 player
- Transferring photos from a phone / camera to another device
- Synchronising calendars on a PDA and a computer