Sedimentary rock forms through the process of lithification, involving the deposition and subsequent cementation of mineral or organic material. These rocks are typically composed of fragments of pre-existing rocks (clasts), precipitated minerals, or compacted biological debris. The formation process involves weathering and erosion, which break down parent material into sediments that are transported by agents such as water, wind, or ice. Once deposited, these sediments accumulate in layers (strata), which undergo compaction and cementation under the weight of overlying materials. Common types include clastic rocks, such as sandstone and shale, which are formed from fragments, and chemical or organic rocks, such as limestone or coal, which result from chemical precipitation or the accumulation of organic remains.