Wide area network
A wide area network (usually abbreviated to WAN) is a data network with extended geographical scope (often country-wide, or even larger). They are constructed out of point-point links connected together with routers. The first WAN's operated at low speed, 9600 baud or 56K baud. With the advent of fiber optics, they now operate at high speed (originally in the range of 1 mega-bit/second, although speeds of 1 giga-bit/second and up are now common).