Lennard's Law describes the relationship between the pressure and volume of a gas at constant temperature. It states that for a given amount of gas, if the volume decreases, the pressure increases, and vice versa. This principle is a fundamental concept in gas laws and helps explain how gases behave under different conditions. The law is often illustrated using the ideal gas law, which combines several gas laws into one equation. While Lennard's Law is a simplified model, it provides a useful framework for understanding the behavior of gases in various applications, such as in engineering and meteorology.