Which protocol is used as a simple file transfer method that operates over UDP?

The Trivial File Transfer Protocol (TFTP) is specifically designed for simple file transfers using the User Datagram Protocol (UDP). This protocol operates without the complexities of connection management and is suitable for environments where ease of file transfer is paramount, and the need for advanced features such as authentication and encryption is limited. TFTP is lightweight and allows for quick transfers, making it ideal for tasks like transferring configuration files to network devices or booting operating systems over a network.

In contrast, other protocols like File Transfer Protocol (FTP) and Secure Copy Protocol (SCP) rely on Transmission Control Protocol (TCP), which ensures reliable delivery of files through connection-oriented communication, adding overhead and complexity that TFTP does not have. Hypertext Transfer Protocol (HTTP), while also operating over TCP, is primarily designed for transferring web content rather than generic file transfers. Thus, TFTP stands out for its simplicity and reliance on UDP, making it the correct choice in this context.