File Transfer Protocol (FTP)
The FTP protocol is an application layer protocol that provides a method for uploading and downloading files from a remote system running FTP server software. FTP uses the TCP transport protocol to guarantee the delivery of data packets.
FTP has some basic security capabilities, such as a capability to authenticate users. However, rather than create a user account for every user, you can configure FTP server software to accept anonymous logons. When you do this, the username is anonymous, and the password is normally the user's email address. Most FTP servers that offer files to the general public operate in this way.
FTP is popular for distributing files over the Internet but is also used within organizations that need to frequently exchange large files with other people or organizations that find it impractical to use regular email.