What is FTP, the File Transfer Protocol?
FTP (or "file transfer protocol") lets people and applications exchange and share data within their offices and across the Internet. FTP was one of the first technologies developed to solve this common need, and it remains, with several generations of enhancements, the second most popular protocol used today (after HTTP or the "World Wide Web").
FTP requires a TCP/IP network to function, and relies on the use of a dedicated FTP server and one or more FTP clients. The FTP server is typically left on (running as a service or daemon) at all times to receive connections from FTP clients. Basic FTP clients are built in to most modern operating systems, including Windows® XP, Windows 7, Windows 8, Mac OS X®, Linux® and UNIX®, or available as free add-ons and mobile apps. Professional FTP clients that include automation and synchronization features are also available for free or a small fee.
Major enhancements to the FTP protocol in recent years include:
- FTPS, or "Secure FTP" secured by SSL/TLS
- SFTP secured with SSH
- Passive mode, or "firewall friendly" transfers
- IPv6 support
- Transfer compression
- Transfer resume, or "checkpoint restart" support
- Time & date synchronization