The Knowledge Base application can be used to provide helpful documentation for a variety of users. This application can be used to configure/display a series of Articles, which can have permissions enforced for limited visibility.
In addition, these Articles are grouped into Categories which can have a separate set of permissions enforced. You are able to setup the Knowledge Base with a hierarchical category structure that suits your needs.
Each category that you create can be configured with an Is Public checkbox. If this option is checked, then users can access that category in the Client Portal without being logged in. On the other hand, leaving this unchecked will require users to be logged in to view/access the category.
When building out the category structure, you can also select the option of Inherit Permissions instead of using the Is Public setting. If this checkbox is selected, then the Is Public permission of the category's parent will be used instead of setting it on the category itself.
The Is Public and Inherit Permissions settings can also be applied to articles, although they will use the associated category's settings. It should also be noted that the root-level of the Knowledge Base application is considered as public.
When articles are created, they must be marked as Published before being visible in the application. However, users who have the See All Articles permission are able to view unpublished articles. The reason for this is that created articles can go through a review process before being made visible.
With this approval process and the ability to configure permissions as needed, you can tailor the Knowledge Base to your needs. You can create public-facing categories and articles that display to everyone who visits the website, while having private categories that contain useful information for your own TD Users.
I hope this provides a good description of how the Knowledge Base works, what you can do to customize it, and how permissions are enforced. Please let us know if you would like further clarification or there is anything else we can do to help you.