The footing of a structure lies on the ground around the base of it and is where the home rests. The foundation itself can go much farther below this component with pilings that are placed deep into the ground. It is responsible for transferring the load directly to the soil and is always below ground level. Foundation walls sit atop footings that are wider than the walls themselves. Footings are traditionally poured on undistributed ground and use piers or pads for vertical support. They are almost always concrete and the footing itself is formed by concrete poured directly into a trench.
Also known as shallow foundations, they are usually embedded into soil. It helps to transfer weight from walls and columns to the bedrock or soil that lies underneath the structure. Another type of footing or shallow foundation is a slab-on-grade foundation. With this type, the weight of a structure is transferred to the soil with a concrete slab on the surface.
An engineer will determine the type of footing (dimensions) to support the structure and the load capacity that works according to that size.