Archaea and Eubacteria are both forms of bacteria. Look at the short definitions of both of them. How are they different?

Despite being in the same category of prokaryotes, archaea and bacteria show variances in their genetic makeup, as the metabolic pathways, and other enzymes, genes possessed by the archaea closely resembles eukaryotes rather bacteria. Simple, microscopic, ambiguous microorganisms mark their presence universally, whether its deep in water, high temperature, soil or any extreme conditions. The evolving history of these cells is considered to be old as more than 3.5 billion years ago. Archaea and bacteria are the representatives of the prokaryotes and belong to the kingdom Monera. Archaea are considered to be the most primitive or ancient forms of life and denote the close relations to the first cells, which is deemed to arise about many years ago on earth. They were earlier classified as bacteria only and obtained name as “archaebacteria”, but due to the presence of certain unique features, they are now termed as ‘archaea’. They are inhabitants of very extreme environments.
Although like bacteria, which occupies the more significant part of the kingdom and are commonly found in the environment, archaea are also single-celled, lacking multicellularity, ranging in few micrometres. These essential differences and similarities are discussed in this content, with a brief description of them.