How do ports on a computer work?

Ports work the same way. ... You can have a total of 65,535 TCP Ports and another 65,535 UDP ports. When a program on your computer sends or receives data over the Internet it sends that data to an ip address and a specific port on the remote computer, and receives the data on a usually random port on its own computer.Mar 24, 2004 read more

Computer ports are an essential feature of all computing devices. Computer ports provide the input and output interfaces the device needs to communicate with peripherals and computer networks. The most important ports on computers are used for computer networking. read more

For example, if a server machine is running a Web server and a file transfer protocol (FTP) server, the Web server would typically be available on port 80, and the FTP server would be available on port 21. Clients connect to a service at a specific IP address and on a specific port number. read more

Your computer then chooses a second port number for that session, different from the "source" port it used for the first session. You could, in fact, do this many, many times, and each session will have a unique "source" port associated with each instance. read more