UDP – Connectionless, very little overhead, used for voice and video traffic, can multiplex using port numbers to work with multiple applications
TCP – Connection oriented, more overhead than udp, uses flow control, sequencing , acknowledgements to ensure reliable, ordered delivery of segments, can multiplex using port numbers to work with multiple applications.
TCP – HTTP, FTP, Telnet, SSH, SMTP
UDP – DHCP, RIP, SNMP, TFTP, DNS
TCP features error recovery, flow control using windowing, connection establishment and termination, ordered data transfer, data segmentation.