Comparing TCP & UDP

TCP provides more features than UDP, but at the cost of additional overhead.

For applications that require reliable communications (for example downloading a file), TCP is preferred.

For applications like real-time voice and video, UDP is preferred.

There are some applications that use UDP, but provide reliability etc within the application itself.

Some applications use both TCP & UDP, depending on the situation.

TCP	UDP
Connection-oriented	Connectionless
Reliable	Unreliable
Sequencing	No sequencing
Flow control	No flow control
Use for downloads, file sharing, etc	Used for VoIP, live video, etc