You've just taken a few giant leaps! You have customized the layout of your new site, framed a structure, and have created and published the contents to match. If this were a static HTML site, this would be about it. This would be all there was to a website. In Joomla!, however, the fun has just begun. You can now add functional or even just plain cool extras. For this, you'll use Joomla!'s components and extensions—that's where the Joomla!'s real magic power lies.
To manage Joomla!'s extended functionality, you'll find yourself working with both the Components and the Extensions menu in the backend. The main difference between these two is that components are more powerful and more complex; they're applications within the Joomla! application. Modules are smaller add-ons that can contain all sorts of dynamic information. Sometimes, components and modules are designed to work together.
So,...