The profile adds a layer of life-narrative to the Human Design chart, over and above the type and centres: it describes the general arc and manner of a person's engagement with the world, in the language of the two lines. The atlas describes the profiles as part of the modern system, noting their derivation from the hexagram lines.
The atlas gives each profile its two lines and its theme. The I Ching hexagrams and lines the profiles derive from, and the wider Human Design chart, are treated in their own categories, within Modern Synthesis Systems.