As an Admin, groups can be super useful for managing and sorting your Viewer users - for example, into regional sales teams or departments. You can make as many groups as you like and users can be members of more than one group so you can adjust as needed at any point!

You can use the “Manage access” feature to restrict the visibility of certain showcases to certain groups only - see Manage User Access for more details on this. 

To see how to add users to a group, check out this article.