Parent rocks are the rocks that undergo weathering to form smaller rocks and soils. Synonyms for parent rocks include source rocks, bedrock, protolith, and substratum. These terms refer to the original rock from which other rocks are formed. The process of breaking down parent rocks into smaller pieces is called weathering, which leads to the formation of sedimentary rocks like sandstone, shale, and limestone. Parent rocks can also give rise to metamorphic rocks like marble and gneiss through heat and pressure. Understanding parent rocks and their synonyms is important for geologists to classify the different types of rocks, study earth's history and formation, and infer mineral deposits and resources.