UDP (User Datagram Protocol) is a transport layer protocol that provides a connectionless, unreliable, and lightweight data transfer service for applications running on IP networks. It is one of the core protocols of the Internet protocol suite and it is often used for real-time applications such as video streaming, gaming, and VoIP. UDP (User Datagram Protocol) sends data packets, called datagrams, to the destination without any guarantee of delivery or order. This makes UDP faster and more efficient than TCP but also less trusted. Sometimes it is used for real-time applications where speed and low latency are more important than reliability.