An intranet is a closed internal network only
available to those computers physically connected
to the network.  Two types of commonly used
intranets are LAN and WAN.  LAN, or local area
network, refers to a network located within a limited
area, such as a building or campus.    The University
Park network is an example of a LAN.  A WAN, or wide area
network, covers large geographical areas.    The
network for the entire Penn State Commonwealth
could be considered a WAN.