Here's a breakdown:

* Water (H₂O) is a liquid at room temperature.

* Heating water increases its energy, causing the molecules to move faster and break free from their liquid state.

* Steam is the gaseous form of water (H₂O). It's still the same chemical compound, just in a different phase.

It's important to note that "gas" is a general term for any substance in the gaseous state. While steam is a gas, it's specifically water vapor.