How do you briefly describe the 3 domains of life?

The three domains of life are Bacteria, Archaea, and Eukarya. Bacteria are single-celled organisms with simple cell structures and no nucleus, while Archaea are also single-celled but have distinct biochemistry and genetics, often thriving in extreme environments. Eukarya includes all organisms with complex cells that contain a nucleus, encompassing a wide variety of life forms, including plants, animals, fungi, and protists. Together, these domains represent the fundamental divisions of all living organisms based on cellular organization and evolutionary relationships.