"Odor molecules" refers to tiny particles that are responsible for creating different smells. They are released from various objects or substances and can be detected by our sense of smell. Full definition
All this complex signal processing means that we can distinguish among thousands of different odor molecules. (discovermagazine.com)
This hypothesis is also based on the assumption that for the ancestors of recent insects, the ability to detect odor molecules in the air rather than dissolved in water was of vital importance. (sciencedaily.com)
Each was a different blend drawn from 128 distinct odor molecules. (discovermagazine.com)