Complex sentence: The specific advantage that XAML brings to WPF is that XAML is a completely declarative language, allowing the developer (or designer) to describe the behavior and integration of components without the use of procedural programming.
Split into simpler sentences: The specific advantage that XAML brings to WPF is that XAML is a completely declarative language. In a declarative programming language, the developer (or designer) describes the behavior and integration of components without the use of procedural programming.