The who command displays the users logged in to the system.

Unless you’re using a server multiple people have access to, chances are you will be the only user logged in, multiple times:

Why multiple times? Because each shell opened will count as an access.

You can see the name of the terminal used, and the time/day the session was started.

The -aH flags will tell who to display more information, including the idle time and the process ID of the terminal:

The special who am i command will list the current terminal session details:

The who command works on Linux, macOS, WSL, and anywhere you have a UNIX environment