Difference between support-v4.app.fragment and app.fragment?
<p>I am new to fragment and here are some questions.
I have update my SDK tool and when I create a project(min = api8, the default one), there is already android-support-v4.jar in my Referenced Library.</p>

<p>And when I extends my class and try to use fragment, I found out there are 2, one is app.Fragment and other is support-v4.app.Fragment, what is the difference between those two?</p>
