What is the difference between TCP and UDP?

TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) are two main transport layer protocols in a network.

Main differences:

• Reliability:

  • TCP provides reliable data delivery by establishing a connection, confirming receipt of packets, and retransmitting lost packets.
  • UDP does not guarantee delivery; packets may be lost, duplicated, or arrive out of order.

• Connection:

  • TCP is connection-oriented. A connection is established before data transfer.
  • UDP is connectionless.

• Speed:

  • TCP is slower due to error checking and acknowledgments.
  • UDP is faster, suitable for applications where speed is more important than reliability (e.g., video, voice calls).

• Order of delivery:

  • TCP guarantees the order of delivery.
  • UDP does not guarantee order.

• Usage:

  • TCP is used for web servers, email, file transfer.
  • UDP is used for streaming, online gaming, DNS queries.

Thus, the choice between TCP and UDP depends on the requirements for reliability and speed of data transmission.