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

The simple statement that helped me get my head around it best was "Could I unit test my business logic without the user interface?" I think this should be the question you ask while learning and designing using MVVM concepts.