Foundation (engineering)
A foundation is the element of a structure which connects it to the ground, and transfers loads from the structure to the ground. Foundations are generally considered either shallow or deep. Foundation engineering is the application of soil mechanics and rock mechanics (Geotechnical engineering) in the design of foundation elements of structures.
Basement
Generally, basements with only an emergency exit well do not count as walk-out. Walk-out basements with at-grade doors on one side typically are worth a lot more, but are more costly to construct since the foundation is still constructed to reach below the frost line. At-grade walk-out basements are on the door-side often used as livable space for the house, with the buried portion used for utilities and storage.