Which protocol’s purpose is primarily to provide a method for applications to send and receive messages?

The chosen answer is Transmission Control Protocol (TCP) because it is fundamentally designed to provide reliable communication between applications over the internet or any network. TCP establishes a connection-oriented communication channel that ensures data packets are delivered in order and without errors. This is achieved through features such as error-checking, acknowledgment of receipt, and retransmission of lost packets.

TCP is essential for applications where data integrity and order are critical, such as web browsing, email, and file transfers. By functioning primarily as a transport layer protocol, TCP enables applications to communicate seamlessly by managing how messages are broken down into packets, sent across the network, and reassembled at the destination.

Understanding TCP's role is important when looking at how different protocols complement each other; for instance, while some options like UDP allow for faster transmission by foregoing reliability, they do not guarantee message order or delivery, making TCP the protocol of choice for most applications requiring dependable communication.