Users and Admins are two different profiles with different permission levels.
A user can only access the Aircall app and won't be able to access the Dashboard. They can receive and make calls from the app and define their personal preferences but cannot modify number settings and other preferences at the account level.
An admin can access the Dashboard from here in addition to using the Aircall app.The dashboard is an interface that allows them to add and configure numbers and users, access call analytics, billing information and more.
If you need further information you can always contact our Support Team, we will be more than happy to help!