Global Permissions -
Global permissions are applied to a global root object that spans solutions, for example, both vCenter Server and vCenter Orchestrator. Use global permissions to give a user or group privileges for all objects in all object hierarchies.
Each solution has a root object in its own object hierarchy. The global root object acts as a parent object to each solution object. You can assign global permissions to users or groups, and decide on the role for each user or group. The role determines the set of privileges. You can assign a predefined role or create custom roles. See
Using Roles to Assign Privileges
. It is important to distinguish between vCenter Server permissions and global permissions.

Reference:
https://pubs.vmware.com/vsphere-60/index.jsp?topic=%2Fcom.vmware.vsphere.security.doc%2FGUID-C7702E31-1623-4189-89CB-E1136AA27972.html
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