frame layout is used to block the area on the screen which will display a single child view. it is difficult to organize multiple views in the frame layout because the views may react differently with different screen sizes as the views may overlap. to avoid this overlapping the use of attribute
android:layout_gravity
will help the developer to organize the views according to his/her needs.
as frame layout was introduced in the API level 1, it is much outdated and there is much better layout present at the moment which will work much better than frame layout.
