W and who commands showing different numbers of users on Linux system

Hello guyz

I am finding it hard to understand how to get the number of users on my system.
When i run the w command it shows me that there are 4 users on my system and the who command only shows 2 users are logged on the system.
Why do the two commands show different numbers of users as per the output below?

What’s the output of this command?


and this command:

who -a

The outputs are below: