Computer network Two or more computers that are connected together to share resources such as hardware, data, and software. Most common are the local area network (LAN) and the wide area network (WAN). A LAN can range from a few computers in a small office to several thousand computers spread throughout dozens of buildings on a school campus or in an industrial park. Expand this latter scenario to encompass multiple geographic locations, possibly on different continents, and you have a WAN.