What is the main characteristic of TCP compared to UDP?

The main characteristic of TCP (Transmission Control Protocol) compared to UDP (User Datagram Protocol) is that TCP ensures reliable delivery of data. This means that TCP establishes a connection before data transmission begins and employs various mechanisms such as error checking, acknowledgments, and retransmissions to guarantee that all data packets are delivered correctly in the proper order. If any packets are lost or corrupted during transmission, TCP can detect this and resend the necessary packets, thus maintaining data integrity.

In contrast, UDP is considered a connectionless protocol that does not provide these reliability features, resulting in faster communication but at the cost of potential data loss. It is simpler and more efficient for applications that do not require guaranteed delivery, such as live streaming or online gaming, but it lacks the robustness that TCP offers for critical data transmission.