Centripetal force is the inward force that keeps an object moving in a circular path, while centrifugal force is the outward force that objects seem to experience when moving in a circle. However, centrifugal force does not exist; it is merely an illusion caused by inertia. Centripetal force, on the other hand, is a real force, such as gravity, tension, or friction, that acts towards the center of the circle. Centripetal force is essential for keeping objects in orbit, spinning around an axis, and moving in circular paths.