The Entity window contains all of the settings used to define the host screens that make up the model. The Entity box contains all of the currently defined entity names with visual indicators to indicate whether each entity listed is "reachable" from the current location via dynamic traversal or navigation.
When you are in offline mode, all screens are considered reachable and display a green icon since the screen shots are loaded from a .snapshot file which has also recorded the navigation of the model. Next to the Entity box, there are three buttons that allow a user to add a new entity, delete the current one, or view the Advanced Entity Properties dialog box.
There are five tabs available from the Entity panel:
See Adding Entities to a Model for information on how to add and define your entity.