(1) See TCP/IP port.

(2) To convert software to run in a different computer environment. For example, the phrase "to port the application to Unix," means to make the necessary changes in the program to enable it to run under Unix.

(3) A pathway into and out of the computer or a network device such as a hub, switch or router. There are numerous ports on the back of every desktop computer for hooking up the keyboard, mouse, modem, printer and network. Laptops have many ports as well, because external monitors, keyboards and mice are generally supported. On network devices, the ports are for communications, typically connecting Ethernet cables or telephone lines. See port speed, line card, serial port, parallel port and PC input/output.