Types of Nonprofits
This is by no means all of the types of nonprofits globally, but here are a few specific ones for the United States.
Nonprofit/Charity/Non-Governmental Organization (NGO)
Generic terms used to denote not-for-profit organizations. NGO is used more internationally, whereas North American usage favors “nonprofit” or “non-profit”. Nonprofits can have various types, and in the US these are commonly denoted by the sections of the US tax code the Internal Revenue Service (IRS) uses to define them:
501(c)(3)
This is what most people view as a traditional nonprofit, also called “public charities”. They are able to accept tax-deductible donations from constituents. In order to maintain tax-exempt status, there are limits on the activities nonprofits can engage in, including not being allowed to politically lobby for or endorse political candidates (although they can promote or fight against specific policy positions).
501(c)(4)
Policy and political action organizations. These organizations are tax-exempt, but donations to them are not tax-deductible. They are, however, allowed to lobby and endorse candidates as long as this is not their primary activity.
501(c)(6)
Membership organizations and business leagues. These are typically dues-based organizations that exist to benefit common business interests (such as trade boards, sporting leagues, etc.).