What is UDP

• UDP is a simpler message-based, unreliable, connection-less protocol.  
  
• UDP does not offer error recovery by re-transmission and flow control to avoid congestion unlike TCP. As a result, many application utilize the UDP because of  significantly low overhead as compared to TCP’s hungry usage.
  
• By providing few services, UDP needs fewer bytes in its header compared to TCP, resulting in asmaller network bandwidth usage.
• UDP is also faster than TCP for transfer of messages because of less overhead.
• UDP doesnt care if the segments are received in an order at the destination. it doesn't even check the order in which they are received.
• UDP is also faster than TCP for transfer of messages because of less overhead.
• With UDP messages (packets) are send across the network in chunks. 
• Some applications do not need error recovery at all , so they use UDP protocol, for example,
  
• notably voice over IP (VoIP) and video over IP
• Live Video streaming such as a basketball match are played over the UDP .

Other applications that use UDP are

• Simple Network Management Protocol (SNMP) – collects valuable network info by polling devices
  
• Trivial File Transfer Protocol (TFTP) – stripped down FTP used to backup and restore routers’ config
  
• Domain Name Service (DNS) – resolves domain names into IP addresses