Joomla! is known as a 'framework' and it is extendable, or in other words, can be added to, with small programs known as 'extensions'. A specific class of those is known as modules and components.
Modules are small applets. They present information on the site to the user. They can be used in a variety of positions and are typically very simple to use and configure.
Components are full-fledged applications and are much more complex. They can only (usually) be displayed within the main area of the page. The typical component requires a menu item to link to it.
Each adds to Joomla! in some fashion that adds functionality or allows better interaction with users.
Modules are not to be confused with module positions in a template. They do work hand in-hand, but are not the same. When you think of module positions, think that this is where they fit. Modules are assigned and fit into module positions.
In this chapter, we'll explore the installation, assignment, and in the case of modules...