2.3.3 User Datagram Protocol (UDP)
User Datagram Protocol (UDP) is one of the core protocols of the internet protocol suite. Using UDP, Programs on networked computers can send short messages sometimes known as datagram’s (using Datagram Sockets ) to one another. UDP is sometimes called the Universal Datagram Protocol.
UDP squeezes extra performance from IP by not implementing some of the features offered by a more heavyweight protocols like TCP. Specifically, UDP allows individual packets to be dropped and UDP packets to be received in a different order than they were sent. Common network applications that use UDP include the Domain Name System (DNS), streaming media applications such as IPTV, Voice over IP (VoIP), trivial File Transfer Protocol (TFTP) and online games.