MVVM facilitates a clear separation of the development of the graphical user interface (either as markup language or GUI code) from the development of the business logic or back end logic known as the model (also known as the data model to distinguish it from the view model). The view model of MVVM is a value converter meaning that the view model is responsible for exposing the data objects from the model in such a way that those objects are easily managed and consumed. In this respect, the view model is more model than view, and handles most if not all of the view’s display logic (though the demarcation between what functions are handled by which layer is a subject of ongoing discussion and exploration). The view model may also implement a mediator pattern organising access to the backend logic around the set of use cases supported by the view.