FTP

FTP, the File Transfer Protocol, standardized as RFC 959 in 1985, is one of the oldest protocols on the Internet — a way to move files between a client and a server over TCP that predates the web itself. It separates control and data connections, supports authentication, and has quietly moved an enormous amount of the world’s data for four decades. It remains a workhorse for bulk exchange even as HTTP-based APIs have become the default for programmatic access.

• Control and data channels - A command connection negotiates the transfer while a separate connection carries the file bytes.
• Authentication and anonymous access - Supports username/password login as well as the classic anonymous FTP pattern for public files.
• Secure variants - FTPS adds TLS, and SFTP (an SSH subsystem, a different protocol) covers the encrypted-transfer use case FTP itself lacks.
• Batch and bulk orientation - Built for whole-file, scheduled, and large-volume transfers rather than fine-grained, real-time interactions.

In modern API operations FTP shows up at the edges: partner data drops, nightly exports, EDI-style batch feeds, and legacy integrations that predate the platforms they now feed. Many providers still expose an FTP or SFTP endpoint alongside a REST API, and part of API strategy is deciding when a real-time HTTP or REST interface should replace a scheduled file drop — and when the file drop is simply the more honest fit for the data. Understanding FTP is understanding where a lot of the API economy actually came from.