What determines your home page?
From Joomla! Documentation
Joomla! is a database-driven content management system (CMS); it does not have HTML pages, but rather assembles the pages from the MySQL database.
When you install Joomla! by default it has a menu link to the frontpage component as the home page. However, any content, component or other link can be used as the home page.
Changing the Home Page
The "page" that shows is determined by the Main Menu. Go to Menu > Main Menu. Select the item you would like as the home page and click the default icon.
- How to determine if the user is viewing the front page (for developers).