Categories group fields into sections. All fields within a category are displayed together in the Specification and various other locations. Each category can also (optionally) have a header / description (Administration in the example below) that can act like third level section if headers with same text are grouped together.
Categories can be added, edited and deleted from this page. To create a new/empty category, simply provide a name and optionally a header/description and press Save.
For existing categories, both names and header/description can be edited by clicking on the pencil icon, editing and pressing Save. Categories can also be re-ordered by grabbing the order id and dragging the category to a new position.
Only empty categories can be deleted. All fields must therefore be removed from a category before it can be deleted.