Categories at the content area are displayed as navigation boxes structure.
The current level categories are displayed with image and capital letter titles. The next sub level is also presented but with smaller font title links.
If the current category has any items attached they will be displayed in a grid below the categories structure.
Categories module is organized as menu tree structure. It displays categories hierarchy and can be placed on every module position.
Categories tree structure is organized as page items. Editing categories page items you can attach or delete new categories, move them up or down in order to arrange the required structure.
You can attach items (products, news, etc. other PageType items) to category by editing the item it self. When you create/edit other PageType item (product for example) there will be a Category tree structure toolbox where you can attach the item to any existing category.
Make sure categories have been enabled for this page type.