Categories are a way of organizing Knowledge Base articles into groups by topic. Users can browse the categories to obtain knowledge on a topic area instead of searching for a specific answer. Note that not all Knowledge Base articles are included in the category structure. They are only added when authors add articles to the categorioes.
You can get to the categories by clicking on the "See More..." link in the "Browse KB Categories" section on the Knowledge Base home page.
The category headers are listed in the left-hand column. Click on a plus sign to expand a section of the tree or click on a minus sign to collapse it. Click on a category's name to see the list or articles in that category.
You add articles to categories by adding the category label to the article. Category labels are formatted c-categoryname. You can find the category label for any category by navigating to that category and scrolling to the bottom of the list of articles in that category. The category label will be listed in the blue highlighted text box. For instructions on how to add labels to articles see: How do I add labels to an article?. If you have trouble finding a category, see: How can I find a category without digging through the category tree?