What are Permission Set Groups and Muting Permission Sets?

Permission Set Groups: Bundle multiple related permission sets into a single assignable group. Instead of assigning 10 individual permission sets to a user, assign one group. Changes to the group automatically apply to all assigned users. Useful for role-based access bundles (e.g., "Sales Rep Access" group containing CRM, CPQ, and Email permissions). Muting Permission Sets: A special type of permission set added to a group to selectively remove specific permissions that would otherwise be granted by member permission sets. For example, a group grants "Delete Accounts" permission from one set, but a muting permission set removes that specific permission. Muting permission sets can only remove permissions — they cannot grant new ones. This enables fine-grained group customisation without creating entirely new permission sets.