Which protocol is used at the application layer to transfer hypertext messages between web clients and servers?

• A. HyperText Transfer Protocol
• B. File Transfer Protocol
• C. Simple Mail Transfer Protocol
• D. Secure Shell

Answer: (A)

HTTP is the protocol used at the application layer to transfer hypertext messages between web clients and servers. It defines the request–response interactions that let a browser ask a server for a resource (like a web page) and the server reply with the resource and metadata. These messages include methods such as GET and POST, a status line, headers, and the body containing HTML, scripts, or other assets. HTTP runs over TCP to ensure reliable delivery and traditionally uses port 80, with HTTPS on port 443 when encryption is required. The other options serve different purposes (FTP for file transfer, SMTP for email, SSH for secure remote access) and are not the standard mechanism for loading web pages, so HTTP is the protocol specifically designed for transferring hypertext between clients and servers.