Vapor

[2] An aerosol is a suspension of tiny particles of liquid, solid, or both within a gas.

Vapor is responsible for the familiar processes of cloud formation and condensation.

It is commonly employed to carry out the physical processes of distillation and headspace extraction from a liquid sample prior to gas chromatography.

The constituent molecules of a vapor possess vibrational, rotational, and translational motion.

Also, vapors obey the barometric formula in a gravitational field, just as conventional atmospheric gases do.

An ampule of nitrogen oxide vapor: brown nitrogen dioxide and colorless dinitrogen tetroxide , in equilibrium
The vapor-liquid critical point in a pressure-temperature phase diagram is at the high-temperature extreme of the liquid–gas phase boundary (the dotted green line gives the anomalous behaviour of water).
Liquid–vapor equilibrium
If the vapor pressure exceeds the equilibrium value, it becomes supersaturated and condenses on any available nucleation sites e. g. particles of dust. This principle is used in cloud chambers , where particles of radiation are visualized because they nucleate formation of water droplets.
Invisible water vapor condenses to form visible water droplets called mist