User Datagram Protocol (UDP) is a communication protocol used for sending data over a network. Unlike its counterpart, Transmission Control Protocol (TCP), UDP does not establish a connection before sending data, which allows for faster transmission. However, this means that there is no guarantee that the data will arrive in the correct order or even arrive at all. UDP is commonly used in applications where speed is more critical than reliability, such as in video streaming, online gaming, and voice over IP (VoIP). These applications can tolerate some data loss, making UDP a suitable choice for real-time communication.