File Transfer Protocol (FTP) is a communications protocol used to send files from computer to computer, with one of them acting as the server, providing the two have an Internet connection.
A networking protocol between client and server, FTP allows users to download web pages, files, and programs that are available on other services. When the user wants to download the information to their own computer, they are using FTP.
FTP does not use encryption. For authentication, it relies on cleartext usernames and passwords, making data transmissions sent over FTP vulnerable to ordinary methods of eavesdropping, impersonation, and other attacks.
“The ubiquity of the internet in concert with FTP for the electronic exchange of documents quickly gave rise to the paperless office concept. Without efficient document delivery, authentication of documents, and — we should add — digital signatures, the internet would be more of a convenience than a path-breaking technology.”