It is a group, organization, institution or corporation formed to provide goods and/or services for a charitable, educational, religious, literary or scientific purpose. Nonprofits' assets are usually donated by companies, foundations or individuals who do not expect to be repaid. These contributions are tax deductible.
On the U.S. Federal level, if a nonprofit meets the requirements of the Internal Revenue Service's Code, section 501(c)(3), it can obtain tax-exempt status, and does not pay federal or state income taxes.
According to candid.org's website grantspace.org [https://grantspace.org/resources/knowledge-base/nonprofit-vs-not-for-profit/]:
Generally, "nonprofit" and "not-for-profit" have the same meaning. However, nonprofit, legal, academic communities do make subtle distinctions between the two terms. Although the words can be used differently by different groups, the simplest way to distinguish between them is to think of ‘not-for-profit’ as an activity, like reading a book. The term ‘nonprofit’ refers to an organization that is not intended to make a profit, like an adult literacy group.
According to the answer to question 1 of New York State Department of State, Division of Corporations, State Records & UCC | Not-For-Profit Corporations FAQs website listed in this guide:
A not-for-profit corporation is a corporation formed pursuant to the Not-for-Profit Corporation Law. It may be formed for as a Charitable Corporation or a Non-charitable Corporation as defined in Not-for-Profit Corporation Law Section 102 (Definitions). [It] may not be formed for pecuniary profit or financial gain and the corporation’s assets, income or profit may not be distributed to or otherwise used to benefit the corporation’s members, directors or officers except as permitted by the Not-for-Profit Corporation Law, e.g., as reasonable compensation for services to the corporation.