UDP is a lightweight, connectionless, TCP used for data transfer. UDP does not have a handshake or connection process, nor does it have a teardown.

To see all your active UDP connections on a Windows machine, open a command line and run netstat -anp udp, as shown in the following screenshot:

UDP doesn't have any ordering or reliability services; it simply delivers the data. Because of this, there isn't a need for a sender (or foreign) IP address and port. As a result, as shown in the following diagram, you will see only a local IP address and port for UDP:

Because of UDP's streamlined nature, it is an appropriate protocol for time-sensitive applications such as Dynamic Host Configuration Protocol (DHCP), Domain Name System (DNS), Trivial File Transfer Protocol (TFTP), Voice over IP (VoIP), and other protocols that require speed. Let's take a look at how a single UDP frame works.