A help desk knowledge base is a collection of information about your product or service that you can use to solve problems or learn how to use it. A modern knowledge base is typically a collection of articles that include text, video, images, and other media and are accessible via the internet. It serves as the product or service's source of truth for its stakeholders, such as customers, employees, and partners.
It is sometimes included in a company's self-service portal. It is sometimes a part of their website.