Topics: Nomenclature, Taxonomic Division, Taxonomic Key, Phylogenic Approach, Phenotypic Approach, Adamsonian Approach, Biochemical Test, Numerical Taxonomy, Phenetics, Taxomerics, Genetic Approach, Genome size, Bacteria DNA, DNA Hybridization, DNA Homology, RNA Sequencing, DNA Sequencing, Protein Profile, Protein Sequence, Ribosome, 16SrRNA Component