Each entity covers a specific aspect of the application design. If you double-click an entity instance in the Design Explorer view, you view this instance in its dedicated editor.
An editor is constituted of tabs. The name and label of the instance are displayed at the beginning of each tab.
Some tabs are common to all entities. In these tabs, you can complete tasks that are available on all entities, such as adding comments or keywords. Other tabs are specific to an entity, so the possible design tasks differ according to the entity.
The Design view is not an editor but a viewer. So, this behavior does not apply. If you modify, in a design editor, the design of an instance that is involved in a generation while the Design view of the generated instance is opened, you can subsequently close the design editor without saving. The modifications are discarded in the design editor and disappear from the Design view.