Hi,
Like we map root level tables, objects, table data permissions into Permission Set. Similarly, we group multiple Permission Sets in a User Group to make the task of assigning permission easier.
In other words, Permission Sets consist of a group of root-level permission on NAv objects (table, page, etc) and the User group is a group of such Permission Sets.
So, ere the advantage is that you don't need to assign the Permission Sets to the individual users by going to the user card. You just tag the user to the required User Group and that user will automatically inherit all the permissions/access for that user group
