LAN (Local Area Network): This setup is a network that connects computers within a given site, building, or home. Most LANs use fixed hardware media connections with fiber optic or copper cable. LANs are sometimes extended using wireless technologies in what is referred to as a wireless local area network, or WLAN.
WLAN (Wireless Local Area Network): This type of network contains computers and devices connected through wireless technologies such as 802.11b and 802.11g. The use of WLANs in homes, business, and retail facilities has exploded. WLANs are normally an extension of a hardwired LAN, but they can also exist in a wireless-only environment.
CAN (Campus Area Network): Although the name of this type of network gives the impression that it is found in an educational environment, the concept of a CAN actually applies to any situation where multiple buildings are networked together. CANs often connect LANs and WLANs. WLANs are becoming an integral component of—and some could say they are replacing— CANs