Joomla was designed to be enhanced. Even though it has lots of built-in features, there are thousands of others that can be integrated to expand Joomla capabilities.

There are three types of Joomla extensions: Components, Modules and Mambots.

Joomla Components

are the most powerful of these three, because they can change the way that Joomla works. Once you install them, they appear in Components menu and add new functionality to Joomla. There you can configure the way they work and appear on your site. OpenSEF, Joomap and DOCman are components.

Joomla Modules

are containers that display information on your site. They can contain anything from plain text, HTML or applications like polls, menus and more. They are extremely usefull, because you can assign them to one, two, or many pages with a few simple clicks. Modules can be user created or installed. Built-in modules are Main Menu, Who`s Online, User Menu, Login Form and some others.

Joomla Mambots

are small (smaller than components) functional units that manipulate content before it is displayed. They can be installed and used with few simple clicks. Some of the built-in mambots are MOS Image, SEF (Search Friendly Mambot) and MOS Rating.

Sometimes Extensions are also called Add-ons. This is a colloquial term for a Joomla extension and it could mean a component, mambot, module or a combination of these three.

So where can I get these cool Add-ons?

Joomla community provides a huge collection of extensions at their Extensions Directory. Most of them are free. Go get them!