This is a list of expalinations and definitions associated with developing using and running Joomla! CMS.

Component

A component is the largest and most complex of the extension types. Components are like mini-applications that renders the main body of the page. An analogy that might make the relationship easier to understand would be that Joomla! is a book and all the components are chapters in the book. The core content component (com_content), for example, is the mini-application that handles all core content rendering just as the core registration component (com_registration) is the mini-application that handles user registration.

Module - Joomla! Extension Directory Module

A more lightweight and flexible extension used for page rendering is a module. Modules are used for small bits of the page that are generally less complex and able to be seen across different components. To continue in our book analogy, a module can be looked at as a footnote or header block, or perhaps an image/caption block that can be rendered on a particular page. Obviously you can have a footnote on any page but not all pages will have them. Footnotes also might appear regardless of which chapter you are reading. Simlarly modules can be rendered regardless of which component you have loaded.

Plugin - Joomla! Extension Directory Plugin

One of the more advanced extensions for Joomla! is the plugin. In previous versions plugins were known as mambots. Along with the development of Joomla! 1.1, mambots have been renamed to plugins and their functionality has been expanded. A plugin is a section of code that runs when a pre-defined event happens within Joomla! Editors are plugins, for example, that execute when the Joomla! event "onGetEditorArea" occurs. Using a plugin allows a developer to change the way their code behaves depending upon which plugins are installed to react to an event.

Language - Joomla! Extensions Directory Language

New to Joomla! 1.1 and perhaps the most basic and critical extension is a language. Languages are packaged as either a core language pack or an extension language pack. They allow both the Joomla! core as well as third party components and modules to be internationalised.