If you want to understand what each permission controls, see User roles and permissions.
Adding users to your business/brand account
To add users, navigate to the bottom left of your page, expand the Settings section, and click into Settings.
Scroll down to "Manage Account Users" then "+Invite Account User."
In most cases, adding an "Admin" user is sufficient (and what we typically recommend). If you want to add a user with limited access, you can do that by selecting "custom" and selecting any features that you want them to be able to access. For details on what each option does, check out the User Roles and Permissions doc
We'll send that person an email with a registration link if they're a new user, or an access link if they're an existing user on a different KnoCommerce account.