Eukarya- eukaryotic, the Eukaryotes
Bacteria- prokaryotic, the true Bacteria
Archaea- prokaryotic, Archaebacteria
The Domain is a relatively new level in the classification hierarchy. It was erected mainly to preserve the kingdoms as we know them. The former kingdom Monera, which included all prokaryotes (lacking a nucleus) , was recently split into two domains, the Domain Bacteria, which includes the true bacteria, and the Domain Archaea, a group of organisms completely unlike the bacteria, except for the lack of a nucleus.