One of the more advanced features of the Facelets framework is the ability to define complex templates containing dynamic nested content.
What is a template?
The Merriam-Webster dictionary defines the word "template" as "a gauge, pattern, or mold (as a thin plate or board) used as a guide to the form of a piece being made" and as "something that establishes or serves as a pattern." In the context of user interface design for the Web, a template can be thought of as an abstraction of a set of pages in the web application.
A template does not define content, but rather it defines placeholders for content, and provides the layout, orientation, flow, structure, and logical organization of the elements ...