What is the primary function of TCP in data transmission?

The primary function of TCP, or Transmission Control Protocol, in data transmission is to verify that packets are sent and received accurately. TCP accomplishes this by ensuring reliable data transfer between devices over a network. It breaks down data into packets and adds sequence numbers, enabling the receiving device to reassemble them in the correct order. Additionally, TCP implements error-checking mechanisms, such as acknowledgments, to confirm successful packet delivery. If a packet is lost or corrupted during transmission, TCP can detect this and request the retransmission of that specific packet. This reliability is crucial for applications like file transfers and web browsing, where complete and correct data is essential for proper functionality.

The focus on verifying packets sets TCP apart from other protocols that handle different aspects of data communication, such as routing, encoding, or physical access to the network.