The bedding of something is its distinct layers in sedimentary rock, differing in grain size, composition, and sedimentary structures. Nearly all bedding was deposited horizontally, parallel to the surface of the earth, as described by the Law of Original Horizontality. Very important to structural geologists because of their use in determining fault movement and Cross-cutting relationships. Bedding is also an integral part of Sedimentology and Stratigraphy. If bedding has not been overturned, it is generally older downward, according to the law of Superposition.