Subsection 501(c) is a subsection of the Internal Revenue Code (IRC)—or what's often referred to as the tax code. It covers nonprofit organizations and tax law; specifically, it lists 12 types of organizations that are exempt from paying federal income tax. The third—501(c)(3)—includes "corporations, funds, or foundations that operate for religious, charitable, scientific, literary, or educational purposes." This is the sort of nonprofit most people are likely to have contact with—the American Red Cross and Direct Relief are two common examples—and to which they donate money.