Which command lists all users currently logged into the system?

The command that lists all users currently logged into the system is the one that displays detailed information about user sessions. When using the command "who," it not only shows the usernames of the connected users but also provides additional context, such as their terminal, login time, and originating IP address or hostname if applicable. This command is particularly useful for administrative tasks when you need to see an overview of all active logins on the system.

While the "w" command also provides information about logged-in users, it includes more extensive details regarding user activities, processes, and system load, which may not be necessary for a simple list of currently logged-in users. The "users" command does show a list of logged-in usernames but lacks the additional context provided by "who." Lastly, "loggedin" is not a standard command in Linux for showing logged-in users. Each of these alternatives serves a specific purpose, but "who" is the most direct and widely used for simply listing current users.