What is the difference between TCP and UDP?

This question is typically posed to assess your technical knowledge and understanding of networking protocols, which are fundamental in many IT and development roles. Interviewers want to evaluate not only your grasp of these concepts but also your ability to explain technical information clearly and effectively. Differentiating between Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) demonstrates your proficiency in network communication and the implications of using each protocol in various scenarios.

Begin by clearly stating the primary difference: TCP is a connection-oriented protocol that ensures reliable communication by establishing a connection and guaranteeing message delivery, while UDP is connectionless and does not guarantee delivery, making it faster but less reliable. For example, you might say, 'TCP is like a phone call where you have a continuous connection and know the message has been received, while UDP is like sending a text message where the recipient may or may not see it.' You could also mention use cases such as 'TCP is used for applications that require data integrity, like web browsing, while UDP is preferred for real-time applications like video conferencing.'