Main Page Content. Component is the largest and most complex of the Extension types. Components are like mini-applications that render the main body of the page. An analogy that might make the relationship easier to understand would be that Joomla! is a book and all the Components are chapters in the book. The core Article Component (com_content), for example, is the mini-application that handles all core Article rendering just as the core registration Component (com_user) is the mini-application that handles User registration. Components work hand in hand with Modules and Plugins to provide a rich variety of content display and functionality aside from the standard Article and content display. They make it possible to completely transform Joomla! and greatly expand its capabilities.