Gas and liquid share the property of being fluids. This means that they can flow and take the shape of their container.

Here's why:

* Gas: Gas molecules are widely spaced and move freely, easily changing shape and volume.

* Liquid: Liquid molecules are closer together than gas molecules but still have the ability to move around each other, allowing them to flow and take the shape of their container.

While both gas and liquid are fluids, they differ in their compressibility. Gases are highly compressible, while liquids are relatively incompressible.