In a modern taxonomic system, a domain made up of prokaryotes that differ from other prokaryotes in the makeup of their cell walls and in their genetics ; this domain aligns with traditional kingdom Archaebacteria
Archaea are a group of single-celled microorganisms that are genetically distinct from bacteria and eukaryotes. They are known for their ability to thrive in extreme environments such as hot springs, deep-sea vents, and acidic environments. Some archaea play important roles in processes like nitrogen fixation and methane production.