m-law
It’s covered in the documentation here:
FAQs can have attachments, HTML/RIch Text and also be associated with specific Help Topics of the Help Desk. This is useful when the clients are searching through the Knowledge Base from the Client Portal; they can select the Help Topic and then only see the FAQs that have been associated with that topic.
So essentially each FAQ can be associated with one or more Help Topic and when the user is looking through the FAQs they can filter them by Help Topic. To configure this for an FAQ go to Agent Panel > Knowledgebase > FAQs > click a Category > click an FAQ > click Edit FAQ > select the relevant Help Topic(s) within the Help Topics dropdown > Save Changes.
Cheers.