15.6.2 Transmission Control Protocol (TCP)

Many applications require information to be delivered accurately and in the correct order. Examples include:

web browsing;
file transfer;
email;
cloud storage; and
remote login.

These applications commonly use the Transmission Control Protocol (TCP).

Before transferring data, TCP establishes a logical connection between the two communicating devices. During transmission it monitors the successful delivery of data, retransmits information that is lost, and ensures that information is presented to the receiving application in the correct sequence.

This reliable service allows applications to exchange information without needing to detect transmission errors themselves. Because TCP performs additional checking and control functions, it introduces greater protocol overhead than simpler transport protocols.