# Overview of user interface services

Orion provides a number of utility services that can be used by scripts on Orion pages. These are not services that would be implemented or used by a plugin. Rather, they provide ways for scripts on each page to contribute links, messages, and commands to the title area, and to display dialogs to the end user. A service is also provided for broadcasting or listening to selection changes, which allows synchronization between multiple widgets on a page. For example, the selection service is used to enable the editor to react to selection changes in the outline panel, and to enable the command service to validate toolbar commands against selections in a list.