One sentence explanation to MVVM in WPF?

Question

I heard its the next best thing in building WPF UIs, but all existing examples have dozens of lines of code - can I get a Hello World for MVVM that explains in no uncertain

Answer 1

An improved answer:

MVVM is all about the future; you want to separate your application logic from the framework so that either the framework can evolve, and your app may not have to change, or your app can evolve and you won't have to worry so much about changing the actual UI aspects.

Actually, MVVM is a refinement of a pattern that has been around for some time. I can remember evolving the pattern when I was working in MFC. There are at least two reasons for doing so. MFC or <> is fairly complex, and mixing MFC constructs in with your application logic makes the application kind of brittle. Example: replacing a listbox with a combobox (or selector in modern terms) is much more difficult if the logic for supporting the content of the list/selector is combined with the logic to manipulate list/selector itself.