Odor, or scent, is the sensory process known as olfaction, which enables the detection of volatile chemical compounds, called odorants, in the ambient air. These compounds, which vary widely in chemical structure, molecules size, and volatility, interact with receptors located within the nasal epithelium. The binding of an odorant to specific receptor proteins triggers a cascade of electrochemical signals. These signals are transmitted through the olfactory nerves to the olfactory bulb, and subsequently to various regions of the brain. This complex neural processing allows the organism to categorize and interpret the perceived odor, linking it to sources, memories, or potential biological meanings. The detection of odor is crucial for physiological functions ranging from detecting spoiled food to identifying airborne threats.