TCP vs UDP

TCP is a connection-oriented protocol, whereas UDP is a connectionless protocol. A key difference between TCP and UDP is speed, as TCP is comparatively slower than UDP. Overall, UDP is a much faster, simpler, and more efficient protocol, however, retransmission of lost data packets is only possible with TCP.

TCP provides ordered delivery of data from user to server (and vice versa), whereas UDP is not dedicated to end-to-end communications, nor does it check the readiness of the receiver.

Features	TCP	UDP
Connection	Requires an established connection	Connectionless protocol
Guaranteed delivery	Can guarantee delivery of data	Cannot guarantee delivery of data
Re-transmission	Re-transmission of lost packets is possible	No re-transmission of lost packets
Speed	Slower than UDP	Faster than TCP
Broadcasting	Does not support broadcasting	Supports broadcasting
Use cases	HTTPS, HTTP, SMTP, POP, FTP, etc	Video streaming, DNS, VoIP, etc