Articles and topics are at the core of your knowledge base.

Articles are the actual content people can read and search for. Ideally they are tied to a topic so they're easy to find, but uncategorized articles are supported and can be found through the search engine.

Use Topics to group related articles together:

They are also important for your Help Center's navigation. For instance, in the following screenshot, Getting Started, Managing Content and Layout & Appearance are all topics.