Water vapor is the gaseous phase of water. It's invisible and occurs when water evaporates or boils, changing from a liquid or solid state into a gas.
This is the process by which water changes from a liquid to a gas or vapor.
The process where water vapor becomes liquid. It's like when dew forms on grass in the morning.
This is when a substance goes directly from a solid to a gas, skipping the liquid phase, like dry ice does.