Wind resistance, also known as drag, is the force that opposes the motion of an object moving through the air. It occurs when air molecules collide with the surface of the object, creating friction that slows it down. The amount of wind resistance an object experiences depends on its shape, size, and speed. For example, a car with a streamlined design will face less wind resistance than a boxy truck. In everyday life, wind resistance affects various activities, such as cycling or running. Cyclists often wear tight-fitting clothing and use aerodynamic helmets to reduce drag, allowing them to move faster with less effort. Similarly, airplanes are designed with sleek shapes to minimize wind resistance, improving fuel efficiency and performance during flight.