The Trivial File Transfer Protocol TFTP is defined in RFC-783 [TFTP:1].
TFTP provides its own reliable delivery with UDP as its transport protocol, using a simple stop-and-wait acknowledgment system. Since TFTP has an effective window of only one 512 octet segment, it can provide good performance only over paths that have a small delay*bandwidth product. The TFTP file interface is very simple, providing no access control or security.
TFTP's most important application is bootstrapping a host over a local network, since it is simple and small enough to be easily implemented in EPROM [BOOT:1, BOOT:2]. Vendors are urged to support TFTP for booting.