What does a port number identify in network communications?

In network communications, a port number serves to identify a specific process or service running on a device. Each port number corresponds to a distinct service or application, enabling the operating system to manage multiple network connections efficiently. For example, web traffic typically uses port 80 for HTTP or port 443 for HTTPS, while email traffic might use port 25 for SMTP. By specifying a port number, data packets can be directed to the proper application, ensuring that the right process receives the information.

This understanding is crucial, particularly when troubleshooting network issues or configuring servers, as it provides insight into how information is routed and managed across various applications. By employing port numbers, the network is capable of handling numerous services simultaneously without conflict, streamlining communication across devices.