Olfactory Information: the property of things by which they are perceptible by the "sensation" they produce in the nose; an "odor," a "scent." (Oxford)
Smells are chemicals, and they can be extremely complex and contain thousands of molecules like the the rose scent, emanating from a flower bed, which is made up of between twelve hundred and fifteen hundred different molecules. Or they can be very simple and comprise just one molecule, like ‘phenylethyl alcohol,’ the chemical that imparts the scent of rose in many commercial hand lotions. (Herz, 18) For humans to be able to smell a chemical, it must be of low molecular weight, volatile, and able to repel water, so that it can stick to our olfactory “receptors.” (Herz, 19) Also referred to as a "smell."
Fragrance: a pleasant, sweet odor. (NCIt) Sweetness of smell; sweet or pleasant scent. (Oxford) More than any other sensory experience, fragrances have the ability to trigger emotions. (Herz, 11)
Odor: the property of a substance that is perceptible by the sense of smell. (Oxford) The sensation that results when “olfactory receptors” in the nose are stimulated by particular chemicals in gaseous form. (NCIt) Studies have shown that odors can literally be transformed into “emotions” through “association” and then act as proxies for emotions themselves, influencing how we feel, how we think, and how we act. (Herz, 11)
Scent: a distinctive, now especially pleasant, odor, as of a flower, etc. (Oxford) We can distinguish an enormous range of scents. We can appreciate novel blends of odors while being able to identify the individual odors that contribute to these blends. (Mathews, 50) The most immediate reaction we have to a scent is an assessment of good or bad. Approach what smells good, avoid what smells bad. (Herz, 14)