网络术语-port number

Port number is part of the addressing information used to identify the senders and receivers of messages.

Port numbers are most commonly used with TCP/IP connections. Home network routers and computer software work with ports and sometimes allow you to configure port number settings. These port numbers allow different applications on the same computer to share network resources simultaneously.

80 - HTTP

21 - FTP

22 - SSH.  Remote administration of unix computers.

8080 - Apatche Tomcat
9080 - WebSphere Application Server HTTP Transport (port 1) default