Which protocol is primarily used for transferring files over the internet?

The primary protocol used for transferring files over the Internet is FTP, which stands for File Transfer Protocol. FTP is specifically designed to enable the transfer of files from one host to another over a TCP-based network such as the Internet. It allows users to upload, download, and manage files efficiently.

FTP operates on a client-server model, where the client initiates requests for files and the server responds by sending the requested files or accepting uploaded files. It typically uses two channels: a command channel for commands and replies, and a data channel for transferring the actual file data. This makes it an effective option for transferring large files or managing batches of files.

While other protocols mentioned are also used for various purposes, they do not serve as the primary means for file transfer. For instance, SFTP (SSH File Transfer Protocol) is a secure version of FTP but is not the original protocol for file transfers. SMTP (Simple Mail Transfer Protocol) is used for sending emails, and HTTP (HyperText Transfer Protocol) is mainly used for transferring web pages and related content rather than general file transfers. Therefore, FTP remains the foundational protocol for transferring files across networks.