Port

(1) An interface on a computer to which you can connect a device.
Personal computers have various types of ports. Internally,
there are several ports for connecting disk drives, display screens,
and keyboards. Externally, personal computers have ports for connecting
modems, printers, mice, and other peripheral devices.

Almost all personal computers come with a serial RS-232C port or
RS-422 port for connecting a modem or mouse and a parallel port
for connecting a printer. On PCs, the parallel port is a Centronics
interface that uses a 25-pin connector.

SCSI (Small Computer System Interface) ports support higher
transmission speeds than do conventional ports and enable
you to attach up to seven devices to the same port.

(2) In TCP/IP and UDP networks, an endpoint to a logical connection.
The port number identifies what type of port it is. For example,
port 80 is used for HTTP traffic. Also see Well-Known
TCP Port Numbers in the Quick Reference section of Webopedia.

(v.) To move a program from one type of computer to another.
To port an application, you need to rewrite sections that are
machine dependent, and then recompile the program on the new computer.
Programs that can be ported easily are said to be portable.