What can TCP distinguish between on the same host?

TCP (Transmission Control Protocol) uses the combination of IP addresses and port numbers to distinguish between different applications running on the same host. Each application typically listens on a unique port number, and by using this port distinction, TCP can maintain multiple simultaneous connections to different services or applications.

When a packet arrives at a host, TCP examines the port number associated with that incoming data to determine which application should receive it. This means that even if there are multiple applications or services running on the same machine, TCP can efficiently direct incoming packets to the correct destination based on the specific port numbers.

This ability to manage and separate traffic for concurrent applications is a critical feature that ensures diverse communication channels can operate independently without interference, maximizing the utility of the networked environment.