who:tldr:40007

The "who -a" command is a Linux/Unix command used to display information about users who are currently logged in and their respective processes.

Here's what each part of the command means:

• "who": This is the main command that shows information about logged-in users.
• "-a": This is an option or flag used with the "who" command. In this case, it stands for "all" and instructs the command to display all available information about logged-in users.

When you run the "who -a" command, it will display a list of users currently logged in, including their username, terminal or session name, date and time of login, and the IP or hostname from where they are logged in. Additionally, it may show information about processes associated with each user, such as the process ID (PID) and the name of the command or program being executed at the time of login.

Overall, this command provides a comprehensive view of users' login information and the processes they are running, which can be helpful for system monitoring, troubleshooting, or managing user sessions.