What Does Simple File Transfer Protocol Mean?
Simple file transfer protocol (SFTP) is an unsecured, lightweight version of File Transfer Protocol (FTP), which runs on Transmission Control Protocol port number 115. It has some useful features not present in Trivial FTP (TFTP), but is not as powerful as FTP.
Techopedia Explains Simple File Transfer Protocol
SFTP supports user authentication where a user has to enter username and password to login into the server. It also features hierarchical folders and file management.