Dutched Cocoa Powder is the dry solid remains of fermented, dried, and roasted cacao beans.
The beans are cracked into nibs, then ground into a paste made of cocoa solids suspended in near-flavorless cocoa butter. Once processors extract the butter they're left with the crumbly solids, which are then ground into a fine powder. So cocoa powder is the core of a chocolate's flavour. Although all cocoa powders can vary in color from light reddish brown to a richer dark brown, the Dutch process gives the powder a noticeably darker hue with a smoother, more mellow and non acidic flavour.
Cocoa butter is obtained from whole cocoa beans which are fermented, roasted, and then separated from their hulls. About 55% of the residue is cocoa butter or cocoa liquor.