Windows Phone 7 is a mobile operating system with a minimum resolution of WVGA and HVGA, 5-megapixel cameras, and hardware acceleration. It uses the Metro design paradigm of being clean, light, open, fast and focused on content over chrome. Applications are built with Extensible Application Markup Language (XAML) and follow a Model-View-ViewModel (MVVM) pattern to separate application data and logic from the user interface. The document provides examples of controls, states, and tasks that can be used to build Windows Phone 7 applications.