CMS Web Design is the design and programming of a Content Managed Site. Content Management means that you, the website owner, has the ability to log in, edit or add new content. This can be in the form of web pages (articles), modules (items on the sides, top and bottom), and web applications (Components like E-Commerce). CMS sites vary in their complexity and versatility, so choosing the right one for you before you get started is important.
The Joomla CMS is an Open Source CMS that is very easy to use, and has an incredible array of extensions to increase it's functionality and look. As of this writing, there are over 10,000 extensions for Joomla that do anything from e-commerce to reservations systems, member subscriptions to auction sites - all easily installed and run without any programming knowledge or experience.
With Joomla, you can also easily install extensions, set them up in minutes, create a menu link to them and your done. It's really that easy.