What is the difference between a global attribute and a user attribute?

Global artifacts

You can use Global attributes to define artifacts. Global attributes are defined at the domain level and made available within artifact types by the Project Owner. When creating artifacts, the values assigned to global attributes become the descriptors for artifacts. Values associated with global attributes are used to search the database for artifacts when using queries. You may find Global attributes like Status, Description, Operating System and the like in your Artifact Type.

User artifacts

Once artifacts are created, you can use User attributes to associate users with artifacts. User attributes are defined at the global level and are associated with a base permission and an email action. Users with the right permission appear in the User attributes menu and can be associated with an artifact using that User attribute. The Assigned To attribute is a User attribute.

For more information on Global attributes see What is a global attribute?.

For more information on User attributes see What can I do with an artifact?.