eZ publish is a content management framework. A base set of features and functions that make up the core of a content management system. It can be used as a system straight out of the box with its standard functionality which provides the majority of the features clients are likely to need. However, often clients require parts of the system to be customized to their needs. This is where the approach taken in the eZ publish framework comes into its strength.
One of the greatest strengths of eZ publish is the way it cleanly separates layers.
In traditional software architecture, there are four layers:
The theory is that each layer should be independent from the other layers so that changes can be made within a layer without affecting the rest of the system. This is also, known as the "black box" concept, that is, the inner workings of one layer is like a black box to the other layers...