This article explains the different roles of Teamcenter Share. This will be required while an Enterprise Cloud Account (ECA) Administrator assigns a role to a user in Teamcenter Share.
Application Owner:
The Application Owner will manage users for the product. They can add/remove users.
Member:
The member user will get the author/contribute permission to the assigned product, so that they could create projects, upload files and share them with others.
If you have any further questions related to this, please open a support case (Product Family= Siemens Xcelerator Admin Console / Teamcenter Share)