UserControl (Composition):
- Contains several existing controls in a reusable "group"
- Consists of XAML and code file
- Cannot use style / templates
- Conclusion from UserControl
CustomControl (extension of an existing control)
- Extends an existing control with advanced features
- Contains a code file and a default style in /Generic.xaml themes
- May be in style / pattern
- The best approach to building a library control
: CustomControls UserControls