Which of the following is a key difference between TCP and UDP in the transport layer of the TCP/IP model?

The key distinction between TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) lies in their approach to reliability and data delivery. TCP is a connection-oriented protocol that ensures reliable communication through mechanisms like acknowledgments, sequencing, and retransmissions. When a packet is lost or corrupted, TCP retransmits it to ensure the data arrives correctly and in order. These features make TCP suitable for applications requiring high reliability, such as web browsing (HTTP/HTTPS) and file transfers (FTP). UDP, on the other hand, is connectionless and prioritizes speed over reliability. It does not provide acknowledgments or retransmissions, which reduces overhead and increases efficiency. Applications like video streaming, online gaming, and VoIP prefer UDP because they tolerate packet loss for better performance and lower latency. ________________________________________ Why Other Options Are Incorrect? 1. TCP operates at the network layer: Incorrect because both TCP and UDP function at the transport layer, not the network layer. The network layer is responsible for IP addressing and routing. 2. UDP uses sliding window mechanisms: Incorrect because the sliding window mechanism is specific to TCP for flow control and congestion avoidance. UDP does not implement any such mechanism. 3. TCP supports multicast transmission: Incorrect because TCP supports unicast only. UDP, however, supports unicast, multicast, and broadcast communication. 4. Handshake process before data transfer: Incorrect because only TCP requires a handshake (three-way handshake). UDP does not establish a connection before data transfer.