A mat foundation is a type of shallow foundation that spreads the load of a building over a large area. It is typically used for structures with heavy loads or when soil conditions are poor. By distributing the weight evenly, a mat foundation helps prevent excessive settlement and provides stability. Mat foundations are often made of reinforced concrete and can be designed to support multiple columns or walls. They are particularly useful in areas with high water tables or weak soil, as they reduce the risk of differential settlement and improve the overall performance of the structure.