Ok, so cocoa and cacao are kind of the same thing. They're also very different.
*le sigh* Let us explain:
The cacao bean is the source of both cacao and cocoa powders. So, “cacao” basically refers to the raw form of chocolate. The cacao bean is what any type of chocolate (cocoa powder) is initially made of.
Actual cacao beans are found inside the fruit of the tree in fleshy, oval-shaped pods. The beans are harvested, fermented, and dried.
When you see cacao nibs, powdered cacao (or cacao powder) in the grocery stores, the bean is in its raw state—uncooked, additive free, and unprocessed.
Cacao contains an abundance of antioxidants, because it's raw and pure. It’s also a fantastic source of fiber, magnesium, essential fatty acids, iron, copper, zinc, sulfur, and calcium.
It isn’t until after the cacao beans are roasted and processed that they are called cocoa. Most cocoa powders have additives like sweeteners or cocoa butter. Once roasted and processed (turning cacao to cocoa), the beans lose much of their nutritional benefits.
There are two types of cocoa powder: Dutch-process cocoa powder is made from cocoa (cacao) beans that have been washed with a potassium carbonate solution, to alkalize the pH and to neutralize their acidity. Dutch-process is dark brown in color.
Natural cocoa powder is reddish-brown and is made from cocoa beans that are simply roasted and ground into a fine powder. Natural unsweetened cocoa powder is actually very similar to raw cacao powder except for experiencing higher temperatures during production, which decreases antioxidant activity.
Or, if you're over the whole thing and just want to ruin cacao for the rest of your life, watch this: