Smells, or odors, are sensations detected by the nose when molecules from substances enter the nasal cavity. These molecules bind to receptors in the olfactory epithelium, sending signals to the brain that identify and interpret the scent. Smells can be pleasant, like the aroma of freshly baked bread, or unpleasant, such as the odor of spoiled food. The sense of smell plays a crucial role in taste and can influence emotions and memories. Certain smells, like lavender, are often associated with relaxation, while others, like smoke, can signal danger. Overall, smells are an essential part of human experience and perception.