Port Numbers





Port Numbers
Port numbers are like the post office box numbers for computers connected to the internet. A port number is a 16-bit number that is used by the internet protocol to identify applications and processes. It is like a street address for each connection made to a computer. For example, when you type in a web address like http://www.example.com, port 80 is used to connect to the server. Port numbers are divided into three ranges: well-known, registered, and dynamic/private. An analogy to help understand port numbers is a class of students. There is a range of students in the class, and each student has a unique number. If the teacher wants to call on a certain student, they use their number to identify them. Similarly, a computer uses port numbers to identify certain applications and processes. A fun fact about port numbers is that the most popular port numbers are 22, 23, and 21, which are used for Secure Shell (SSH), Telnet, and FTP, respectively.