Difference between TCP and UDP
by UDP or User Datagram Protocol is the simplest connectionless transport layer protocol which simply sends packets between applications. It has very less overhead as UDP doesn’t require any session to transfer packets between applications.
Generally Real time protocols (RTP), DNS etc application uses UDP protocol.
TCP or Transmission Control Protocol is a reliable, connection-oriented protocol. TCP maintains a session between application and uses this session to send data across applications. TCP has support of acknowledgements of every packet being transferred and hence it’s reliable protocol but has higher overhead compared to UDP.
Generally FTP, HTTP etc application uses TCP protocol.