The abbreviation SFTP is used for both Simple File Transfer Protocol, a simple, low-function transfer protocol dating back to 1984, and the FTP protocol secured via Secure Shell, SSH File Transfer Protocol.
SSH File Transfer Protocol (SFTP) is a protocol for secure file transfer. The Secure File Transfer Protocol and Secure FTP are the most widely used transfer techniques for secure file transfer. The SFTP protocol is an evolution of the FTP protocol that transfers control and user data in an unsecured manner. Like the Secure Copy Protocol( SCP), which has been largely superseded by SFTP, the SFTP protocol uses an encrypted connection via Secure Shell (SSH2), which serves as the transmission basis for the SFTP protocol.
In contrast to the Secure Copy Protocol (SCP), the SFTP protocol offers the possibility of accessing, editing and managing files on other people's computers in addition to pure file transfer. For example, it can interrupt the file transfer and restart it at the interrupted point, it can list directories and remove files. For transport, the SFTP protocol standardized by the Internet Engineering Task Force( IETF) uses the TCP protocol.
The SFTP protocol is designed for file transfer over Secure Shell. It is not backward compatible with the traditional FTP protocol, which means that no communication is possible between SFTP clients and FTP servers or FTP clients and SFTP servers. However, there is client and server software that overrides these limitations. In the Apple world, the corresponding SFTP protocol is called Fetch (V.5) and works under Mac OS X.