Ext JS provides numerous UI elements that are essential to developing rich Internet applications (RIAs). Ext JS includes controls such as message boxes, combo boxes, data grids, and toolbars. In addition, layout managers allow you to specify how elements are displayed on a page. Additional features are available for working with forms and windows.

The include order for the JavaScript files can change if you are using other frameworks. However, Ext JS is typically included in your Web application, assuming that you've installed Ext JS in the lib/ext directory on your Web server.