Originally, the term "White Paper" designated an official British document printed on white paper; specifically, "a parliamentary consultation or Command Paper outlining proposals for future policy or legislation on a particular subject" (OED). "White Paper" was shorthand for a government report, authoritative and informative in nature.
The definition has broadened and today it include documents issued by companies and organizations, as well as government agencies.
According to Purdue OWL, "A white paper is a concise report that often informs readers about an issue or an authoritative report that talks about a specific proposal. A white paper usually contains proposals for a specific policy or talks about an issue in detail. This document can be used in various industries—ranging from business to politics to science."
According to the FAO, "A policy brief is a concise summary of a particular issue, the policy options to deal with it, and some recommendations on the best options. It is aimed at government policymakers and others who are interested in formulating or influencing policy."
Policy Centers & Nonprofit Organizations