In the XUL world, Chrome is the top level window which contains groups of UI elements of various types. Example of chrome are the <b>browser window</b> and <b>dialog window</b>. The chrome obtains its UI description from four types of providers:  * Content provider::Provides the skeleton, i.e., the menus, command buttons* Skin provider::Supplies the look-and-feel of the chrome* Platform provider::Gives platform dependent UI description* Locale provider::Offers the language and culture sensitive resources