Both solids and liquids have a fixed volume. This means that their volume doesn't change easily, even if you change the shape of the container they're in.

Here's why:

* Solids: The particles in a solid are tightly packed together in a fixed arrangement. They can vibrate, but they can't move freely, so they maintain a constant volume.

* Liquids: The particles in a liquid are closer together than in a gas, but they can move around each other. While the particles can move, they are still close enough together to maintain a constant volume.

Important Note: While solids and liquids have fixed volumes, they have different shapes:

* Solids: Have a fixed shape.

* Liquids: Take the shape of their container.