In an MVVM implementation, is every ViewModel coupled to just one Model?
I am trying to implement the MVVM pattern in a project but I found
I would make sure you understand the difference between view, viewmodel, and all other model classes. The ViewModel is the model object that is filled with data that the view can be bound to. It just exists to provide data to the view, which makes the ViewModel object unit-testable, and the whole business logic separate from the view. So, you can develop your business logic entirely without using the view itself, and can replace the view with just building or using another view and binding to the ViewModel object's properties. If a view is full of empty text fields for example, the contents of the text fields can be bound to different properties of the view model.
There usually really should only be one view model. BUT if it's too complex, you can use subproperties of the bound objects like described in Binding to ViewModel.SubClass.Property (sub-property)
The ViewModel can get the data it returns to the view from a lot of different sources, business objects, databases, whatever.