Bernoulli's Principle states that as the speed of a fluid increases, its pressure decreases. This means that in areas where a fluid, like air or water, moves faster, the pressure is lower compared to areas where it moves slower. This principle helps explain how airplanes generate lift, as the air moves faster over the wings, creating lower pressure above them. This concept is named after the Swiss mathematician Daniel Bernoulli, who introduced it in the 18th century. Bernoulli's Principle is essential in various fields, including aerodynamics, hydraulics, and even in understanding how venturi tubes work in measuring fluid flow.