The User Datagram Protocol (UDP) is a very simple protocol in the Computer Network. Its inserts are limited to the fundamental functionality of Internet Protocol (IP). Like IP, it is an uncertain, connectionless protocol.
We do not require to establish a connection with a host before exchanging data with it by using UDP. Also, there is no structure for providing information if the data which is sent is properly received or not. A unit of data transmitted by using UDP is known as a Datagram.
UDP inserts four 16-bit header fields (8 bytes) to whatever data is transmitted. These fields are a length field, a checksum field, and a source and destination port number. In this context, we can describe a software port, but not a hardware port. The approach of port numbers is common to both UDP and TCP.
The port number identifies which protocol module is sent (or receive) the data. Most of the protocols have standard ports that are frequently used for this. For example, the Telnet protocol typically uses port 23. The Simple Mail Transfer Protocol (SMTP) needs port 25.
The need for standard port numbers is created and it is achievable for the users to transmit with a server without first establishing which port to use.
The port number and the IP header's Protocol field duplicate each other to some range, though the protocol field is not possible to the higher-level protocol. IP uses the protocol field to decide whether data should occur to the UDP or TCP module.
UDP or TCP facilitate the port number to decide which application layer protocol should receive the data. Although UDP is not reliable, it is an appropriate choice for many applications. It is used in real-time applications like Net audio and video, where if the data is lost, it is better to send it again out of sequence. It is also used by a protocol like the Simple Network Management Protocol (SNMP).
UDP is an unreliable protocol and we will need a UDP protocol in some terms. It is deployed where the packets need a vast amount of bandwidth along with the basic information.
For example, in video streaming, accepting thousands of packets is troublesome and wastes bandwidth. Some packets loss cannot create a problem in video streaming, and it can also ignore it