Beauty of ADF- Taskflow, Difference b/w Facelets and JSP XML fragments in bounded taskflow

Oracle ADF framework support modular architecture for enterprize application development. Multiple small module can be bound together to form a large module .
The greatest advantage of ADF controller over core JSF navigation model is that it splits a single bulky module to multiple reusable and interconnected modules known as Taskflows.

i am not going deeper in Taskflows as every ADF developer know about it ,so the important part is page fragment.

• When  we create taskflow as bounded taskflow , and check it to create fragment in taskflow.

• Now when we create pagefragment in bounded taskflow, there is 2 option for creating fragment

Create fragment as Facelets
Create fragment as JSP XML 

Facelets- is default and official view handler for JSF pages, priviously JSP was used to view JSF pages but it didn't support all component so Facelets comes in picture under APACHE open source license. It supprts all UI component used by JSF (Java Server Faces).
Facelets was developed by Jacob Hookom in 2005.
If you create Facelets fragment in bounded taskflow, then taskflow must be dropped in a JSF page (parent page) not in .jspx (JSP XML ) page.
if you try to drop it into JSP XML page-

JSP XML- jspx is XML variant of JSP(Java Server Pages) to support XML document . JSP XML fragments are used in ADF inorder to support XML document and more powerful page validation techniques.
If you create jsp xml fragments in bounded taskflow, then taskflow must be dropped in a JSP XML(.jspx) page(parent page) not in JSF page.