UDP (User Datagram Protocol)
UDP (User Datagram Protocol) is another Tranport Layer Protocol. It is simpler than TCP. It is generally used in unsenstive communications and real time applications that do not need a secure data transmission mechanims.
UDP is a Connectionless Protocol. There is no need to establish a session to use UDP.
UDP is not a Reliable protocol. UDP do not care about if the data is received or not. Generally applications that provide its own Error-recovery, use UDP. This make UDP, a Best Effort (fast) protocol. So, generally UDP used for real time applications, that need fast and efficient transmission such as voice calls, video calls, games etc.
UDP is susceptible to the data loses, duplicate traffic and non-orderly delivery. It only concentrate on Best-Effor (Fast) transmission.
There is no Ordering Mechanism in UDP. If any order is required, the Application Layer do this for that traffic.
UDP Header is very simple. It has source address, destination address, length and checksum areas. The total UDP Header is 8 bits.