Aerodynamics is the study of how air moves around and interacts with solid objects, such as airplanes, cars, buildings, and even animals. It is a branch of fluid dynamics that deals with the motion of air and other gases. Aerodynamic forces are used to explain how objects move through the air, and how they interact with each other. Aerodynamics plays an important role in the design of aircraft and automobiles, as well as many other engineering applications.