As you've seen throughout this book, there are a huge number of extensions for Joomla! that provide features you can add to your Joomla! website with little hassle.

By default, any HTML that these extensions provide is usually defined by the author of the extension in the extension's \views directory. Joomla!'s content component has its HTML defined within the components\com_content\views directory. This means that the HTML that is generated for say, the "article" type of content, is stored in components\ com_content\views\article\tmpl\ as default.php. To overwrite the way the HTML is output for this view, you can simply copy the default.php file from this directory to your own Joomla! template directory. For example, if rhuk_milkyway is the name of the Joomla! template that you're using, then you store your template override in the templates\rhuk_milkyway\html\com_content\article\ directory as default.php.

Template overrides can be used to overwrite what Joomla! outputs at the module and component level. This means that you're able to customize Joomla! on a component basis (such as the "article" example mentioned earlier), as well as being able to customize what is output for modules (for example, a "latest news" block on your Joomla! website's home page).