The most common system for classification at the domain level consists of the Prokaryota and the Eukaryota. At the Prokaryota level, organisms are often unicellular and lack a nucleus and other membrane bound organelles. An example of these types of organisms would be bacteria and archea.

Contrastly, Eukaryotes are organisms which contain membrane bound organelles and a nucleus. This domain is very diverse and contains everything from a single celled protist, to a sunflower, to a African elephant, and everything in between.

Bald eagles fall into the domain of Eukaryota.