Microsoft introduced XAML as a part of Windows Presentation Foundation (WPF), which saw the light of day back in 2006. XAML is basically a declarative model to define UIs with an object model, among other things, that represent the objects put in the XAML. This is what represents the view in the MVVM setting.
XAML puts a lot of effort into binding declaratively from the view to what is called the datacontext. The model is hierarchical, meaning that one can set a context at a higher level and it inherits the context deeper within the hierarchy, but at any given place in the hierarchy, a node can redefine what the context is and everything is now relatively bound to the context unless an explicit source is specified. Binding is done through something called markup extensions; these are basically expressions expressed through curly brackets ({ }). Bindings have the ability to observe changes in the object they are bound to; it does this by recognizing interfaces that allow you to...