You Can add unlimited number of categories and sub-categories.

To Add a category you need at least Insert Category Name.

You can choose if category is Main Category or you can Choose its parent category to become sub-category for parent category.

You can choose a unique color for Main Category.

Each category has its own SEO Keywords & Description which can be added from admin panel.

You Can Drag and Drop Categories to Re-Order Them.
When you delete category, all related sub-categories and news will be deleted But you have the choice to move them to another category before delete.