The protocol used for transferring files on the internet is FTP, the File Transfer Protocol.
FTP was designed for moving files between a client and a server. Its original specification was written by Abhay Bhushan and published in 1971, making FTP one of the internet’s earliest application-layer protocols. Unlike ordinary web browsing, FTP traditionally uses separate connections for commands and file data.
FTP became widely used for uploading website files, downloading software, and exchanging files with remote servers. It is often confused with HTTP, which primarily delivers web pages and web resources, or SMTP, which sends email. Telnet is instead used for interactive remote terminal access.
Plain FTP is not secure: usernames, passwords, commands, and file contents can be transmitted unencrypted. Modern systems often prefer SFTP, which runs over SSH, or FTPS, which adds TLS encryption. These are related alternatives, but they are not the same protocol as FTP.