FTP

Abbreviation · Development

Definitions

  1. FTP, or File Transfer Protocol, is a standard network protocol used for transferring files between a client and a server over a TCP/IP network. Developed in 1971 and standardized in RFC 959, FTP is one of the oldest internet protocols still in use. It operates on a client-server model using two channels: a command channel (typically port 21) for sending commands and receiving responses, and a data channel (port 20 or a negotiated port) for actual file transfers. FTP supports both active and passive modes, with passive mode being more firewall-friendly. A significant limitation is that standard FTP transmits credentials and data in plaintext, making it vulnerable to eavesdropping. SFTP (SSH File Transfer Protocol) and FTPS (FTP over TLS) address this by encrypting the connection. While FTP has been largely replaced by SFTP, SCP, and HTTP-based file transfer in modern workflows, it remains in use for legacy systems, hosting providers, and automated batch file transfers.

    In plain English: A protocol for uploading and downloading files between computers over the internet, like a digital file courier.

    Example: "We still have a legacy integration that drops CSV files on an FTP server every night — one day we'll migrate it to an API."

Etymology

1971
FTP was first specified in RFC 114, making it one of the oldest internet protocols still in use.
1985
RFC 959 defined the modern FTP specification that became the standard.
2010s
FTP usage declined in favor of SFTP, SCP, and HTTP-based file transfer, though legacy systems still rely on it.

Origin Story

The First Language Computers Spoke to Each Other

FTP, the File Transfer Protocol, is one of the oldest internet protocols still in use. It was first specified on April 16, 1971, in RFC 114, written by Abhay Bhushan, a graduate student at MIT. This was years before the World Wide Web, years before email protocols were standardized, and only two years after the first ARPANET message was sent between UCLA and Stanford in 1969. Bhushan's protocol allowed users to log into remote computers and transfer files between them. The original FTP was designed for the ARPANET's Network Control Protocol (NCP) and was later updated for TCP/IP as the internet evolved. RFC 765 (1980) and RFC 959 (1985) refined the protocol into the form still recognized today, with separate control and data connections. FTP became the backbone of early internet file sharing. Before the web, if you wanted to download software, you used anonymous FTP to connect to public file servers. University computing departments, software archives, and early Linux distributions all relied on FTP mirrors. The protocol's lack of encryption became a major concern as the internet grew: usernames and passwords travel in plaintext. SFTP (SSH File Transfer Protocol) and FTPS (FTP over TLS) addressed this, and most modern workflows have replaced FTP with HTTPS or cloud storage.

Coined by: Abhay Bhushan

Context: MIT / ARPANET, RFC 114, April 1971

Fun fact: FTP is older than email. Abhay Bhushan wrote the FTP specification in 1971, while the first email specification (RFC 524 for mail over ARPANET) did not appear until 1973.

Related Terms