Taxonomic rank refers to the hierarchical classification system used in biology to organize living organisms. This system categorizes species into various levels, such as domain, kingdom, phylum, class, order, family, genus, and species. Each rank represents a different level of relatedness among organisms, with species being the most specific and domain being the broadest. Each taxonomic rank helps scientists communicate about and study biodiversity. For example, the domestic cat belongs to the kingdom Animalia, the phylum Chordata, and the genus Felis, ultimately identifying it as Felis catus at the species level. This structured approach aids in understanding evolutionary relationships.