File transfer

File transfer is a generic term for the act of transmitting files over a computer network or the Internet. There are numerous ways and protocols to transfer files over a network. Computers which provide a file transfer service are often called file servers. Depending on the client's perspective the data transfer is called uploading or downloading.

There are 2 types of file transfers:

• Pull-based file transfers where the receiver initiates a file transmission request
• Push-based file transfers where the sender initiates a file transmission request

File transfer can take place over a variety of levels:

• Transparent file transfers over network file systems
• Explicit file transfers from dedicated file transfer services like FTP or HTTP
• Distributed file transfers over peer-to-peer networks like Bittorent or Gnutella
• File transfers over instant messaging or LAN messenger
• File transfers between computers and peripheral devices
• File transfers over direct modem or serial (null modem) links, such as XMODEM, YMODEM and ZMODEM

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

• List of file transfer protocols
• File sharing