Define an I/O port. Which functions are performed by it?

I/O port is an input output port of a computer which is capable of receiving (input) and sending (output) data. The main function of a I/O port is to send and receive data. As it is used to transfer data. Device such as keyboards is an input device and printer is an output device.

For example - Modem is an input output port and device where we can connect it with the computer is called I/O port.