When inviting users to join your Workspace you must select which User Type they will be. There are two Workspace User Types:
The difference between the two types is determined by the choices you make in the Advanced section of the Workspace Settings.
You can choose to allow either only Owners or both Owners and Members to:
Manage users - remove users or change their access levels
Have access to Billing
See Stacker Support
View Workspace Settings incl. the list of members and their access levels
Edit Workspace Settings incl. the name and appearance.
You cannot confer powers for the above to only Members and not Owners and in this sense, Owners are by default a higher level of access for the Workspace.
See the linked article below for instructions on inviting Workspace Users: