The word that fits the definition you provided is "classification system." Biologists use a classification system, often referred to as taxonomy, to place organisms into specific taxonomic groups based on their characteristics and evolutionary relationships. The classification system involves a hierarchical structure with various levels of classification, including kingdom, phylum, class, order, family, genus, and species. Organisms are grouped into these taxonomic ranks based on shared characteristics and evolutionary history. By using a classification system, biologists can organize and categorize the immense diversity of organisms found in the natural world.
