It is through the aromas of wine that wine is tasted. The human tongue is limited to the primary tastes perceived by taste receptors on the tongue-acidity, bitterness, saltiness, sweetness and savoriness. The wide array of fruit, earthy, floral, herbal, mineral and woodsy flavor perceived in wine are derived from aroma notes interpreted by the olfactory bulb. In wine tasting, wine is often smelled before being drunk in order to identify some components of the wine that may be present. Different terms are used to describe what is being smelled. The most basic term is aroma which generally refers to a "pleasant" smell as opposed to odor which refers to an unpleasant smell or possible wine fault. The term aroma may be further distinguished from bouquet which generally refers to the smells that arise from the chemical reactions of fermentation and aging of the wine.