Components are larger extensions that produce the major content for your site. Each component has one or more "views" that control how content is displayed.In the Joomla! administrator there are additional extensions suce as Menus, Redirection, and the extension managers.
The contact component provides a way to provide contact forms and information for your site or to create a complex directory that can be used for many different purposes. Help
The search component proviedes basic search functionality for the information contained in your core components. Many third part extensions also can be searched by the search component. Help
The users extension lets your site visitors register, login and logout, change their passwords and other information, and recover lost passwords. In the administrator it allows you to create, block and manage users and create user groups and access levels. Help
Please note that some of the user views will not display if you are not logged in to the site.