Navigation Drawer is a Fragment, it is used when we need to show more than 5 "Navigation items" on the Screen.
Its open like a Drawer so, that's why we say Navigation Drawer.
For Creating a Navigation Drawer Fragment we need to use "DrawerLayout" on Layout of Navigation Drawer.
This is the main Activity page , If you clicked on three lines of left side of the Screen, then you see the Navigation Drawer Fragments :-
This is Navigation Drawer looks Like:-
You can see the Purple Color, Header Layout on the top of the Navigation Drawer Fragment, That is Called Header Layout. Header Layout is created in new resource file in Layout Folder.
Then we used Header layout in our Navigation Drawer's Layout file by the Help of "NavigationView".
You can see Home, Gallery and Slideshow these are fragment items, we can set Functionality on it, Right Now i set new Activity on it.