What is the primary use of the Telnet protocol?

The primary use of the Telnet protocol is to enable remote access to a server computer. Telnet allows users to connect to a remote machine over a network and interact with it as if they were physically present at the location. This is achieved through a command-line interface where users can input commands and receive responses from the remote host.

Telnet operates primarily over TCP and utilizes port 23 by default. Although it facilitates effective communication between a client and a server, it's important to note that Telnet sends data, including passwords, in plaintext without encryption, making it less secure compared to other remote access protocols, such as SSH (Secure Shell). The utility of Telnet is particularly evident in environments where users require a straightforward terminal interface for managing servers or devices from a distant location.

Other options relate to functions that Telnet does not inherently provide. Securing local network connections and encrypting communications are not associated with Telnet's functionality, nor is it designed for monitoring network traffic. The distinct role of Telnet emphasizes its purpose as a means of remote connectivity rather than security or monitoring.