Networks:

These are computers linked together into a network to share information and programs.

Some are housed in a small geographic area such as in an office or building and are called LANs (local area networks).  They may be connected by cabling or telephone wires.

Other networks that cover a wide geographic area, such as across several states, are called WANs (wide area networks).

The main computer of a network is called the server.  This computer is the very powerful and may provide access to shared devices, such as a network printer.  The server controls access to the programs, files and devices on the network.  Computers that connect to the server are called clients.  

WebTV:

For those who don't have access to a computer but would like to get access to the Internet, there is a special TV called WebTV.  This TV enables you to connect to the Internet and usually also includes a keyboard or other device for entering and selecting data.