* Volume: Every object, including a stone, takes up space, which is called volume.
* Water's Incompressibility: Water is mostly incompressible, meaning it doesn't easily squish down to take up less space.
* Displacement: When you drop the stone into the glass, it pushes some of the water out of the way to make room for itself. This is displacement.
* Overflow: If the glass is full to the brim, there's no room for the displaced water to go, so it spills over the edge.
Think of it this way: The stone takes up space that was previously occupied by water. Since water can't compress to fit in a smaller space, it has to go somewhere, and that somewhere is over the edge of the glass!
