A category is a grouping of Objects. A knowledge-base based on the standard Template will display the following categories;
The category image (visible in the Object Catalog) and name can assigned via the Category Editor which can be invoked by right-clicking the Category name in the Object Catalog tab and selecting 'Edit' from the menu.
New categories can be added to the Object Catalog by using the Add a new Catalog Category tool under Advanced Tools.
If this tool is not available, click the expansion icon in the top-right of the 'Build Tools' pane and check the 'Show Hidden Tools' checkbox.