What Is a Whitepaper?
A whitepaper is a persuasive, authoritative, in-depth report on a specific topic that presents a problem and provides a solution.
Marketers create whitepapers to educate their audience about a particular issue, or explain and promote a particular methodology. They're advanced problem-solving guides.
What Is a Whitepaper Not?
A product pitch.
Although Investopedia defines a whitepaper as "an informational document issued by a company to promote or highlight the features of a solution, product, or service," overtly shilling your own stuff could turn off readers.
The goal of a whitepaper is to inform and persuade based on facts and evidence, not tell the world why people need to buy your product right now.
However. Of course this does happen. Let it be a red flag for you when you do your research.