File transfer

File transfer is the transmission of a computer file through a communication channel from one computer system to another. Typically, file transfer is mediated by a communications protocol. In the history of computing, a large number of file transfer protocols have been designed for different contexts.

Some examples of file transfer:

• Network file systems may allow transparent file transfers
• FTP is an older cross-platform file transfer protocol
• Secure copy (scp) is based on the Secure Shell (SSH) protocol
• HTTP can support file transfer
• Bittorent, Gnutella and other distributed file transfers systems use peer-to-peer
• In IBM Systems Network Architecture, LU 6.2 Connect:Direct and XCOM Data Transport are traditional
• Many instant messaging or LAN messenger systems support the ability to transfer files
• Computers may transfer files to peripheral devices such as USB flash drives
• Dial-up modems null modem links used XMODEM, YMODEM, ZMODEM and similar

Protocols

A file transfer protocol is a convention that describes how to transfer files between two computing endpoints. They are meant solely to send the stream of bits stored as a single unit in a file system, plus any relevant metadata such as the filename, file size and timestamp.

File transfer protocols usually operate on top of a lower-level protocol in a protocol stack. For example, the HTTP protocol operates at the topmost application layer of the TCP/IP stack, whereas XMODEM, YMODEM, and ZMODEM typically operate across RS-232 serial connections.

See also

• File sharing
• List of file transfer protocols
• Managed file transfer
• Peer-to-peer file sharing
• Pull technology
• Push technology