An IP address is a unique address that certain electronic devices use in order to identify and communicate with each other on a computer network. Any participating network device including routers, switches, computers, time-servers, printers, Internet fax machines, and some telephones have their own unique address. Similar to a home or business address supplying that specific physical location with an identifiable address, devices on a network are differentiated from one another through IP addresses. A computer uses DNS servers to look up a hostname to find its IP address. Most IP addresses look like this: 151.101.65.121