Maybe the idea behind composite components originates from the fact that JSF page authors and JSF component authors have different perspectives regarding components. While JSF page authors perceive components as tags that can be used in XHTML pages, JSF component authors see components as a mixture of UIComponent, UIComponentBase, NamingContainer, Renderer, Validator, and Converter elements—these are elements that shape up a JSF component. Based on this, it seems that custom components can be written only by JSF component authors, since they have knowledge about these JSF elements and Java language. This fact, however, has begun to change as of JSF 2 and composite components, which are practically custom components written in XHTML pages using markup tags. This means that JSF page authors can start writing their components without having the same level of knowledge and skills as dedicated JSF component authors—at least, simple, composite components.

For example...