Alright, I'll give you some reasons why Joomla is more powerful than Wordpress.
-Multiple Templates:
You can install multiple templates in Joomla and then assign the to different sections of your website selecting the *menu link* for which you want a give template to display. This means you can have completely different looking pages of your website, that can serve a variety of different functionalities.
-Module Position Assignment:
This one is big. When you create a template, you can set Joomla code that generates the content for a specific module position. Then, when you assign module, you assign it to a position name the specific *MENU LINK* for which you want that module to appear. You could even create a menu link that's assigned to an entire *SECTION* of content, so that a given module can appear on every page in that section. Remember the templates above? They can work the same way too!
-Plugins:
Joomla plugins are extensions which specifically *ACT* on content. They don't make the page you see, they just make it look different. There's plugins that can auto-generate specific code (like other articles by this author) on in articles. There's plugins that that can replace blocks of text (like {joomlaplugin} ) with other modules, components or other custom code. There's plugins whose function is to extend search capability, editor functionality and more.
-Components:
Think of them like programs you install on your website. You could have a component that is a project manager, a shopping cart, a forum or even just gives you a unique way of organizing content and displaying it on a given page.
-THE JOOMLA FRAMEWORK
HERE'S THE BIG ONE: Joomla is a CMS that is built on the JOOMLA FRAMEWORK. The Joomla Framework, as far as I have seen so far, is the MOST ROBUST *AND* EASY TO USE OPEN-SOURCE TOOL-SET for building web applications (using php/html/css/java/mysql).
