Dashboard widgets are small, independent JavaScript code modules that are run separately from the standard JavaScript environment, which is the Web browser. In fact, you can open widgets in most browsers and have them function quite similarly to how they behave in Dashboard. As such, when you launch Dashboard, you're basically launching a Web browser environment that can use the same plug-ins that your browser uses. This also means that when you try to update some software that requires Web-based environments to be shut down (Adobe updates--Reader, Flash, and so on), the dashboard can prevent them from being installed.
