The Linked Work tab is where you can view all linked work items of a Ticket or Case.
Note that Sub-Cases created via the '+ Work item' link will still display in the 'Sub Cases' tab for the time-being, and do not show in the Links tab.
Within the Links tab grid you can a list of Linked work item, showing their reference, title, assignee, Queue and due date of a work item.
There is also an icon to unlink the work item if they have been linked in error.
You can also expand linked Cases to see their Actions.
If you don't have permissions on a certain business process, the work items from that process will be greyed out and you won't be able to open or edit them. You'll still be able to see higher level information about the work item, e.g. who they're assigned to, which Queue they're in and when they're due.