The Contenido Principle - flexible and modular

Layouts, Modules und Templates work together to determine where and how your content is displayed. When creating a Layout, Contenido first adds the skeletal structure of the page, along with special keywords for the "Container" (placeholder).
 
You can create your own layout using your knowledge of HTML, a proprietary WYSIWYG HTML editing programs such as GoLive or DreamWeaver, or one of any number of freeware and open-source.
 
Once the Layout is complete, you'll be using Modules to display individual articles and content elements. Contenido provides its own simple modules for displaying content; with some knowledge of PHP, however, you'll quickly be able to extend on these and use your modifications on your website.
 
Layouts and modules work together in Templates. In a template you determine what contain (modules) will appear in the layout's "containers".