An NGO is a non-governmental organization. While the funds used are often provided from government sources, the organizations are not a direct part of a government. They are also known as civil society organizations.
Non-profit organizations (NPOs) or not-for-profit organizations (NFPOs) gather funds in various ways, such as donations, endowments and by other forms of fundraising. Nonprofit organizations use funds for the specified mission of the organization, rather than providing funding to a corporation or to shareholders; they are usually organized or chartered for a social or service purpose, and are often tax-exempt. Not-for-profit organizations are more commonly more loosely organized around a particular locale, task or purpose, and are usually not tax-exempt. Nonprofits and not-for-profit organizations may have other specific local, state and national legal definitions and rules.
(paraphrased from http://www.differencebetween.net/business/difference-between-ngo-and-non-profit-organizations, accessed 5/30/2014)