What is a URL?
Each Internet application (ftp, telnet, http, etc.) is associated with a unique port number. For example, the port number associated with web resources is 80 by default.
Occasionally, a web resource is accessed through a different port number. In these instances, the port number needs to be specified. For example:
If a port number is not specified in a URL, it is assumed to be 80 and does not need to be specified. For example: