What is White Paper?

Legal Definition
A white paper is an authoritative report or guide that informs readers concisely about a complex issue and presents the issuing body's philosophy on the matter. It is meant to help readers understand an issue, solve a problem, or make a decision. The initial British term concerning a type of government-issued document has proliferated—taking a somewhat new meaning in business. In business, a white paper is closer to a form of marketing presentation, a tool meant to persuade customers and partners and promote a product or viewpoint. White papers may be considered grey literature.
-- Wikipedia
Legal Definition
1. Prelude to the final document on policy. 2. Marketing tool on information of underlying technology and how a customer can benefit.