How to work with fragments_main.xml in Android API19 rev3?

Question

Android

Hey guys! Most likely, the question will seem too miserable to you.
The fact is that to replace my old Wildfire S with 2.3.3 on board, I bought myself a Nexus 5 with 4.4.2, respectively. I downloaded the newest SDK, I create a simple project without bells and whistles, and there is some fragments_main.xml there. My friends, who have the penultimate version, do not have this 0:
Can someone throw some info on how to work with it?

Answer 1

You can remove it and make the project work as by default (just remove the extra code).
Or you build an application using fragments, which is good =)