What is the actual seed in the fruit of the macadamia tree?

Fruits of the macadamia tree are woody, hard shells, very difficult to break and have an edible part inside. Culinary people call them nuts, but in botany, they are not nuts, just fruits.

If I take a typical macadamia fruit (intended to be eaten, but sold still in shells), crack the shell, how do I find what is the pericarp, mesocarp, endocarp and what part is the seed?

What are the anatomical parts of the edible and inedible layers of the macadamia tree fruit?