A plain landform is a large expanse of flat, sweeping terrain with little variation in height. Within a common region, it is quite level and does not fluctuate greatly in height. This sort of landform is lower than the surrounding landmass and may be found both inland and along the shore. Many different types of plains exist, including coastal plains, valley bottoms, and uplands. They are one of the four major forms of landform that cover up the earth.