A rock slide, also known as a rockfall, is a geological event in which rocks break loose from a slope and tumble down to the ground below. Alternative terms for rock slide include landslip, mudslide, debris flow, rock avalanche, and rockfall. A landslip occurs when the soil and rocks on a slope become unstable and slip downhill. A mudslide is similar to a rock slide, but it involves soil and water along with rocks. Debris flow is a type of fast-moving landslide that typically includes a mixture of rocks, soil, and water. Rock avalanches are massive boulder falls that can create huge clouds of dust and debris. Rockfall refers to the individual rocks that fall from a slope during a rock slide event.