White papers are persuasive marketing documents that provide in-depth information about a company's products or services. There are three main types of white papers: backgrounders, which provide features and benefits of a product or service; numbered lists, which present tips or key points about an issue; and problem/solution papers, which outline an industry problem and propose a solution. White papers are intended to educate readers and generate leads for a company. They should be promoted through various online channels like social media, websites, and email to maximize their visibility and impact.