What are smells primarily composed of?

Smells are primarily composed of vapors, which are tiny particles of substances that have evaporated into the air. When a substance transitions from a liquid or solid state to a vapor state, it releases odor molecules that can be detected by our olfactory receptors. This is why we can perceive various smells, as the vaporized molecules bind to receptors in our nasal passages, sending signals to our brain that interpret these scents.

Although gases can also play a role in the formation of smells, vapors are specifically involved in the release and detection of odors. Vapors are often used interchangeably with gases in everyday language, but in the context of smells, vapors refer to the airborne molecules that arise from liquids and solids.