Greater granularity surrounding what users can and cannot do (actions/operations). Not to be confused with Permissions (access to Matters and content).
Historically, LexWorkplace provided limited granularity around Rights and Group membership. With this new (pending) feature, nearly every available action/operation in LexWorkplace has a corresponding Right that can be enabled or disabled for any given Group.
By using Groups + Rights Management, firms can tightly control what actions certain users/groups can perform (and which they cannot).