Tree views can be used for navigating through hierarchically related items. For example, using a tree view of organization items you can show the organizational structure of the organizations involved in using Service Desk. Also, the hierarchical structure of workgroups and configuration items can be shown in tree views. In a tree view you can display items that do not have a hierarchical structure, however the items are then shown in a way similar to a list.
The image below shows an example of a tree view.