You will find a list of All Registered Users under the Users section on the admin panel.
From here, you can access information about everyone who has signed up on the platform. Unlike Data Studio which lists profiles (i.e. even records on your database of people who may or may not have signed up) by default, this list shows you only people who have registered on the platform.
This view is useful to see the registration status of users. Alternately, you can also use the 'Registration Status' filter on Data Studio.
You can check here on what each of the terms within ‘Registration Status’ mean.
For a better understanding, check out this article on understanding the signup process.