Mass movement is the movement of masses of bodies of mud, bedrock, soil, and rock debris, which commonly happen along steep-sided hills and mountains because of the gravitational pull. That means, air, water or ice do not carry debris with them from place to place but on the other hand, the debris may carry with it air, water or ice. The movements of mass may range from slow to rapid, affecting shallow to deep columns of materials and include creep, flow, slide and fall.
Mass movements do not come under erosion though there is a shift (aided by gravity) of materials from one place to another. Weak unconsolidated materials, thinly bedded rocks, faults, steeply dipping beds, vertical cliffs or steep slopes, abundant precipitation and torrential rains and scarcity of vegetation etc., favour mass movements.