What is a port number?

A port number lets your computer handle many types of network communication simultaneously by labelling each type with a number.

Your IP address is like a building's street address. Port numbers are like apartment numbers they tell the operating system which program should receive incoming data.

Common standardised ports:

• Port 80: regular web (HTTP)
• Port 443: secure web (HTTPS)
• Port 22: SSH (remote access)
• Port 25: email (SMTP)
• Port 3306: MySQL database

Port numbers range from 0 to 65,535. Ports below 1024 are reserved for well-known services.