What are Internet ports?
Although your computer has a single IP address on the Internet, a variety of functions and software are involved in an Internet connection . For example, receiving email, sending email, viewing a Web page, using a newsgroup, and uploading files are all different processes, with each using different software methods. In order to carry out these various functions in a systematic way, use is made of numbered “ports” as local addresses. (These ports have no physical existence and are not to be confused with actual things such as USB or parallel ports.) These local addresses are used to direct the various types of Internet activity to the appropriate software on the local computer. Think of your computer as an office building, with different rooms used to carry out various functions. The usual IP address would correspond to the street address of the building and the ports would correspond to room numbers. In fact, the standard form of an URL ( the human-friendly equivalent of the numerical
