Hi,
what is the exact usage of KB categories and of Business Hours?
thanks in advance
For business hours see https://docs.suitecrm.com/admin/administration-panel/advanced-openadmin/
The KB Categories are just a way to group KB articles. So if you create a category “Tutorials” you can group a few knowledge base articles under that label.
both of these are really simple functionalities, they don’t have complicated explanations because they don’t have much to explain 
Thanks a lot