A white paper is an informative report that explains a complex issue and presents the sponsor's philosophy on the matter. These documents are meant to help readers understand an issue, solve a problem, or make a decision.

The term originated in the early 20th century to mean a type of position paper or industry report published by a department of the UK government. Earlier forms of these reports were called "command papers".

White papers are used often in business, and sometimes in politics and academia. Since the 1990s, these documents have proliferated as sales or marketing documents in business; for more than 10 years, a majority of business-to-business (B2B) marketers report that they created a white paper within the past year. A commercial white paper is akin to a marketing presentation designed to promote a certain product to customers. As such, it can be considered content marketing or grey literature.

The most prolific publishers of white papers today are business-to-business companies. These white papers are long-form content that use selected facts and logical arguments to promote the offering(s) from the company sponsoring the report. The main goal is to persuade target readers in a certain vertical market or role to agree with the sponsor's conclusions and select their offering. In most companies, white papers are created by content marketing teams or the contractors they hire, based on online research and interviews with company executives.

Corporate white papers are often used to generate sales leads, establish thought leadership, make a business case, grow email lists, grow audiences, and build the sponsor's credibility. The audiences for a B2B white paper can include prospective customers, channel partners, journalists, analysts, bloggers, investors, or any other stakeholders.

White papers are considered a form of content marketing or inbound marketing; in other words, sponsored content available on the web with or without registration, intended to raise the visibility of the sponsor to search engines and build web traffic. A B2B white paper generally argues that one particular technology, product, ideology, or methodology is superior to all others for solving a specific business problem.

The term white paper originated with the British government, with the Churchill White Paper of 1922 being an early example. In the British government, a white paper is usually the less extensive version of the so-called blue book, both terms being derived from the colour of the document's cover.

White papers are a "tool of participatory democracy ... not [an] unalterable policy commitment". "White papers have tried to perform the dual role of presenting firm government policies while at the same time inviting opinions upon them."

In Canada, a white paper is "a policy document, approved by Cabinet, tabled in the House of Commons and made available to the general public". The "provision of policy information through the use of white and green papers can help to create an awareness of policy issues among parliamentarians and the public and to encourage an exchange of information and analysis. They can also serve as educational techniques."

White papers are also used in academic settings to present research findings to peers. Academic white papers often follow strict styles and formats, such as the Common Technical Document (CTD) standards.

Some key areas where academic white papers are published include computer science, cryptography, mathematics, medicine, physics, and IT security.

Instead of relying on the self-governance used in journalism, academic white papers rely on the feedback provided by industry leaders or experts in a field. The overall findings they provide, in the form of public peer-reviews, creates the necessary "checks-and-balances" that academics rely on to evaluate a conclusion.