Lung volumes refer to the different amounts of air that the lungs can hold during various stages of breathing. These volumes are typically measured using a device called a spirometer. The main lung volumes include tidal volume, which is the amount of air inhaled or exhaled during normal breathing, and vital capacity, the maximum amount of air a person can exhale after a deep breath. Other important lung volumes include residual volume, the air remaining in the lungs after exhalation, and total lung capacity, which is the sum of all lung volumes. Understanding these volumes helps in assessing lung function and diagnosing respiratory conditions.