Trivial File Transfer Protocol (TFTP) is a very low overhead file transfer service that runs over UDP port 69. In contrast to File Transfer Protocol (FTP), which has at least minimal security features, TFTP has no meaningful security. All messages are sent in the clear, and no authentication is required to establish a connection. Files can be copied and retrieved using simple, well-publicized commands.
TFTP is primarily used in trusted local networks for fast or automated file backup and restoration. TFTP is used in Cisco environments for this purpose.
See RFC 1350.