The force responsible for circular motion is called centripetal force. This force acts towards the center of a circular path, keeping an object moving along that path rather than moving off in a straight line due to inertia. Centripetal force can be generated by various sources, such as tension in a string, gravitational attraction, or frictional force between a surface and an object. It is essential for the stability of objects in circular motion, such as planets orbiting a star or a car navigating a curve.