The protocol primarily used for transferring files over the Internet is FTP (File Transfer Protocol). FTP enables users to upload, download, and manage files on servers. It operates on client-server architecture, where the FTP client communicates with the server to facilitate file transfers. FTP is widely utilized for transferring large files and managing websites. Enhanced security variants like SFTP (Secure FTP) and FTPS (FTP Secure) have emerged to ensure secure data transmission.