The block sets the boundaries for the stage.
There are four types of stages for Physics Engine: boxed with roof, boxed without roof, open with floor, and open without floor.
Boxed with roof
The stage is packed with boundaries on all sides of the stage.
Boxed without roof
The stage has 3 boundaries – left, right, and bottom sides. The top side is open for the sprites to move. In this example, we are pushing 4 balls in different directions to see how they move on the stage.
Open with floor
The stage is open on the top, left, and right sides. The stage has a boundary only on the bottom side which act as the floor.
Open without floor
The stage is open on all sides. The sprites can move in all directions.