Everyone knows that Content is King, and in eZ Platform, everything is Content!
Take a look at the content model underlying eZ Platform.
Content model overview
The content structure in eZ is based on ideas borrowed from Object-Oriented programming, as seen in popular languages such as C#, Java or PHP.
In this understanding an "object" in the eZ Platform is called a Content Item and represents a single piece of content: an article, a blog post, an image, a product, etc. Each Content item is an instance of a "class," called a Content Type.