Define the word archeobacteria in its simplest way
Archaea (/ɑːrˈkiːə/ (listen) ar-KEE-ə; singular archaeon /ɑːrˈkiːən/ ar-KEE-ən) is a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotes. Archaea were initially classified as bacteria, receiving the name archaebacteria (in the Archaebacteria kingdom), but this term has fallen out of use. Archaeal cells have unique properties separating them from the other two domains, Bacteria and Eukaryota. Archaea are further divided into multiple recognized phyla.