A port number is a unique identifier used by networks to direct internet traffic to the correct application or service. Common examples include port 80 for HTTP, port 443 for HTTPS, and port 22 for SSH. Understanding ports is essential for configuring servers, firewalls, hosting environments, and network security. Correct port management can also prevent connection problems and reduce unnecessary security risks. Read the full Port Number article to learn how ports work and discover the most commonly used port numbers.