What is TCP vs UDP difference?

• A. TCP is connection-oriented with reliability; UDP is best-effort, lower overhead.
• B. TCP is stateless; UDP is connection-oriented
• C. Both are irrelevant for data transfer
• D. UDP provides guaranteed delivery

Answer: (A)

The difference being tested is how the two transport protocols handle data delivery. TCP is connection-oriented and reliable, while UDP is a lightweight, connectionless best-effort protocol.

TCP establishes a connection, uses acknowledgments and retransmission to ensure data arrives correctly and in order, and includes flow control and congestion control to manage the data rate. This reliability and ordering come with extra overhead and some delay.

UDP, on the other hand, sends independent datagrams without establishing a connection and without guarantees of delivery, ordering, or duplication protection. Its headers are smaller and processing is simpler, so it’s faster and uses fewer resources, which is ideal when low latency matters or when the application can tolerate some loss.

In practice, TCP is used for most reliable communications like web traffic and file transfers, while UDP is favored for time-sensitive tasks such as real-time audio/video, online gaming, or simple query-response services (like DNS).

So the correct description is that TCP provides reliability and is connection-oriented, whereas UDP is best-effort with lower overhead.