Network Definitions
Computer networks can be classified and defined according to geographical area that the network covers. There are four network definitions: a Local Area Network (LAN), a Campus Area Network (CAN), a Metropolitan Area Network (MAN), and a Wide Area Network (WAN). There are three additional network definitions, namely the Internet, an intranet and an Internetwork. These network definitions are discussed in Table 1.2.
| Definition | Description |
| Local Area Network (LAN) | A LAN is defined as a network that is contained within a closed environment and does not exceed a distance of 1.25 mile (2 km). Computers and peripherals on a LAN are typically joined by a network cable or by a wireless network connection. A LAN that consists of wireless connections is referred to as a Wireless LAN (WLAN). |
| Campus Area Network (CAN) | A CAN is limited to a single geographical area but may exceed the size of a LAN |
| Metropolitan Area Network (MAN) | A MAN is defined as a network that covers the geographical area of a city that is less than 100 miles. |
| Wide Area Network (WAN) | A WAN is defined as a network that exceeds 1.25 miles. A WAN often consists of a number of LANs that have been joined together. A CAN and a MAN is also a WAN. WANs typically connected numerous LANs through the internet via telephone lines, T1 lines, Integrated Services Digital Network (ISDN) lines, radio waves, cable or satellite links. |
| Internet | The Internet is a world wide web of networks that are based on the TCP/IP protocol and is not own by a single company or organization. |
| Intranet | An intranet uses that same technology as the Internet but is owned and managed by a company or organization. A LAN or a WAN s usually an intranet. |
| Inter network | An inter network consists of a number of networks
that are joined by routers. The Internet is the largest example of an inter network. |
TABLE 1.2: Network Definitions
Of these network definitions, the most common are the Internet, the LAN and the WAN.