How many bits are used to identify ports in TCP?

In TCP (Transmission Control Protocol), ports are identified using 16 bits. This means that each port number can range from 0 to 65535 (2^16 - 1). The 16-bit field for ports allows for a practical number of unique ports, which is important for managing multiple connections and services on a single host. Each port number is used to distinguish different services that are running on a server or to help identify specific connections between hosts during network communication.

Understanding this structure is essential in networking, as different services (like HTTP, FTP, etc.) are typically assigned specific ports within this range. For example, HTTP uses port 80, while HTTPS uses port 443. The 16-bit designation allows for efficient routing of the traffic to the correct application on the receiving device based on these port numbers.