Trivial File Transfer Protocol (TFTP) is a method often used to transfer files across a local area network (LAN). This method uses UDP, which is the least secure protocol for transferring data. Therefore it is strongly suggested to only use TFTP on a local network.
TFTP can be used to set up a Pre-boot Execution Environment (PXE). We can boot to a Linux operating system using the network, without having to flash an disk image onto the computers hard drive or a USB.