Utility widgets: ResourceLinks widget
Utility widgets are not part of a specific module and do not display content from the CMS in the frontend. They help administrators, designers, or developers to perform their jobs.
The main widget for the theming of Sitefinity CMS backend is ResourceLinks widget located in namespace Telerik.Sitefinity.Web.UI. The purpose of the widget is to link to resources and you must use it only to add resources that can be different in various themes. You can also use the widget for theming your own user widgets and pages.
The ResourceLinks widgets can be used in the following cases: