It is called foundation to the set of structural elements of a building whose mission is to transmit its loads or elements supported on it to the ground; Distributing them in such a way that they do not exceed their permissible pressure nor produce zonal loads. Because the soil resistance is; usually; Smaller than that of the pillars or walls it supports; The area of ??contact between the floor and the foundation must be proportionally larger than the supported elements; Except in very coherent rocky soils. The foundation is important because it is the group of elements that support the superstructure. The stability of a building depends to a large extent on the type of terrain on which it sits.