Generally speaking a foundation is a philanthropic non-profit organization, set up either by individuals or institutions, with the purpose of distributing grants to worthy causes, similar to charitable trusts or to maintain a facility or preserve some heritage. Sometimes they give out money and some foundations seek charitable donations to support their purposes.
In civil law jurisdictions the foundation finds its source in institutions of medieval times when a patron would establish a foundation to endow a monastery or other religious institution in perpetuity. The foundation has a distinct patrimony independent of its founder and if it is not a moral person it is considered to be a social trust.
List of a few North American Foundations
In architecture, the foundation of a building is the portion of its structure that serves to transfer the weight of the building into the ground itself. Most foundations extend underground, and the foundations of large buildings often penetrate the bedrock.