An odor or odour or fragrance is caused by one or more volatilized chemical compounds, generally at a very low concentration, that humans or other animals perceive by the sense of olfaction. Odors are also commonly called scents, which can refer to both pleasant and unpleasant odors. The terms fragrance and aroma are used primarily by the food and cosmetic industry to describe a pleasant odor, and are sometimes used to refer to perfumes. In contrast, malodor, stench, reek, and stink are used specifically to describe unpleasant odor. The term smell (in its noun form) is used for both pleasant and unpleasant odors.
In the United Kingdom, odour refers to scents in general. In the United States and for many non-native English speakers around the world, odor generally has a negative connotation, as a synonym for stink; on the other hand, scent or aroma are used by those people to indicate "pleasant smells".
The sense of smell gives rise to the perception of odors, mediated by the olfactory nerve. The olfactory receptor (OR) cells are neurons present in the olfactory epithelium, a small patch of tissue in back of the nasal cavity. There are millions of olfactory receptor neurons that act as sensory signaling cells. Each neuron has cilia in direct contact with air. The olfactory nerve is considered the smell mediator, the axon connects the brain to the external air. Odorous molecules act as a chemical stimulus. Molecules bind to receptor proteins extended from cilia, initiating an electric signal.
My brain is haunted by this scent
it takes me back to a past event
it's like a drug that I need every day
I need to preserve it, have to get it my way
Forever I'll have this desire
this scent - keeps me alive and fills my soul
Forever engulfed by its fire
this scent - consumes my mind and takes control
The feelings I get when memory comes back
goves me something in my life I lack
it takes me awat to the place I seek
and my being reaches its highest peak
I follow the trail it leaves behind
boxing it up is on my mind
preserving this scent is my aim
I satisfy my senses, that scent must sustain.