What is User Datagram Protocol (UDP)?

The User Datagram Protocol (UDP) is an IP network protocol which does not require prior communication to set up communication channels or data paths between different hosts.

UDP provides checksums for data integrity, and port numbers for addressing different functions at the source and destination of the datagram. It has no handshaking dialogues, and thus exposes the user's program to any unreliability of the underlying network; there is no guarantee of delivery, ordering, or duplicate protection. If error-correction facilities are needed at the network interface level, an application may instead use Transmission Control Protocol (TCP).