Port 80 is commonly used to refer to TCP port 80. The port usually used by the HTTP protocl.
Port 80 is almost always used to refer to the TCP port used for the http protocol.
It is closely related to port 8080 and sometimes port 81,...
Most other web browser ports are either derivative of port 80 (such as 8080) or port 443, the SSL variant for more secure TCP connections.
