Why is a FrameLayout used for fragments?

Question

Wherever I look, FrameLayout seems to be used as the FragmentContainer. Why is FrameLayout always seen with Fragments?

Answer 1

You can basically use RelativeLayout or LinearLayout it will still work,but the answer of your question is in FrameLayout's documentation :

FrameLayout is designed to block out an area on the screen to display a single item. Generally, FrameLayout should be used to hold a single child view, because it can be difficult to organize child views in a way that's scalable to different screen sizes without the children overlapping each other. You can, however, add multiple children to a FrameLayout and control their position within the FrameLayout by assigning gravity to each child, using the android:layout_gravity attribute.

You can read more about FrameLayout here : FrameLayout/Android Developers