What is the difference between TCP and UDP?

The distinction between TCP and UDP lies primarily in their operational characteristics. TCP, or Transmission Control Protocol, is connection-oriented, meaning that it establishes a reliable connection between two endpoints before data transmission begins. This ensures that all packets are delivered accurately and in the correct order, as TCP includes mechanisms for error-checking, acknowledgments, and retransmissions for lost packets. This makes TCP suitable for applications where data integrity and order are critical, such as web browsing, email, and file transfers.

On the other hand, UDP, or User Datagram Protocol, operates as a connectionless protocol. It sends data packets without establishing a prior connection or guarantees about delivery. Because of this lack of overhead in maintaining a connection and the absence of error-checking and retransmission features, UDP tends to be faster than TCP. This speed makes UDP ideal for applications where speed is more important than reliability, such as video streaming, online gaming, and other real-time applications where dropping some packets may be acceptable.

In essence, the correct choice highlights these fundamental differences: TCP's connection-oriented, reliable nature versus UDP's connectionless, faster approach.