Building a simple computer network

A simple computer network may be constructed from two computers by adding a network
adapter (Network Interface Controller (NIC)) to each computer and then connecting them
together with a special cable called a crossover cable. This type of network is useful for
transferring information between two computers that are not normally connected to each
other by a permanent network connection or for basic home networking applications.
Alternatively, a network between two computers can be established without dedicated
extra hardware by using a standard connection such as the RS-232 serial port on both
computers, connecting them to each other via a special crosslinked null modem cable.
Practical networks generally consist of more than two interconnected computers and
generally require special devices in addition to the Network Interface Controller that each
computer needs to be equipped with. Examples of some of these special devices are hubs,
switches and routers.