I've been programming for a long time now, and I have always seen Model classes exactly as a business entity. For instance: sales, users, products, orders, etc...But I have come to certain source codes (specifically in MVVM applications in WPF) where Model not only include business entities, but several other types, and now I'm confused.What exactly represents model classes, are they limited to business objects or what else do they include? If I could get a couple of examples, that'd be good.
is a Model exactly the same as a Business Entity?
design patterns;architecture
My understanding of MVVM is that the term model doesn't refer to a specific model, but to the entire domain model.I think the confusion comes from the fact that many View Models (in my experience) exist to enable CRUD operations on an Entity.  That makes it seem like model refers only to a single entity model.But a View Model doesn't need to be confined to that simple scenario.  The entirety of your domain data and logic (the domain model) could be exposed through a single View Model without violating MVVM.