UDP advantages

Simplicity ...

for the network, not the programmer

Does not include the overhead needed to detect reliability and maintain connection-oriented semantics

UDP packets require considerably less processing at the transmitting and receiving hosts

Does not maintain the illusion of a data stream

packets can be transmitted as soon as they are sent by the application instead of waiting in line behind other data in the stream; similarly, data can be delivered to the application as soon as it arrives at the receiving host instead of waiting in line behind missing data

Less heavy to manage for the OS

Many operating systems impose limits on how many simultaneous TCP/IP connections they can support.

Operating system does not need to keep UDP connection information for every peer host, UDP/IP is more appropriate for large-scale distributed systems where each host communicates with many destinations simultaneously