The View is the client interface, input-output interface or the user interface. It collects all the user interface elements of the window, navigation page, user control, resource file, style and themes, custom tools and controls. The view is unaware of the ViewModel and the Model, and vice versa the ViewModel and Model is unaware of the View and control is tightly decoupled.
But the view model is aware of the needs of the view. They communicate by data binding and a dependency property or properties.
ViewModel in MVVM
ViewModel is a non-visual class. The MVVM Design Pattern does not derive from any WPF or Silverlight based class. The ViewModel is unaware of the view directly. Communication between the View and ViewModel is through some property and binding. Models are connected directly to the ViewModel and invoke a method by the model class, it knows what the model has, like properties, methods etcetera and also is aware of what the view needs.
One View-Model can connect to multiple models, work like a one-to-many relationship and encapsulate business logic and data for the View. A ViewModel inherits some interface like
INotifyPropertyChanged, icommand INotifyCollectionChanged etcetera.
