What is the primary difference between transmission control protocol (TCP) and user datagram protocol (UDP)?

The primary difference between transmission control protocol (TCP) and user datagram protocol (UDP) lies in their approach to data transmission and reliability. TCP is a connection-oriented protocol, which means it establishes a reliable connection between the sender and receiver before any data is transmitted. It ensures that all segments of the data are acknowledged and re-sent if they are lost during transmission. This tracking mechanism allows TCP to provide reliable delivery of messages.

In contrast, UDP is a connectionless protocol that sends messages without establishing a dedicated end-to-end connection. It does not track whether the messages are successfully received or not. This lack of tracking is what makes UDP a faster option for data transfer, as it minimizes the overhead associated with connection management and error checking. However, it also means that some messages may be lost without notice, which is acceptable for certain applications, such as streaming audio or video where speed is more critical than complete reliability.

Therefore, the choice stating that "TCP messages are tracked to ensure they are received; UDP messages are sent without tracking" accurately captures this fundamental distinction. While one might consider UDP to be faster, that information alone does not define the primary difference, which fundamentally revolves around the reliability and connection handling of the two protocols. The other options