The biological classification system for living organisms is known as taxonomy. This system categorizes organisms based on shared characteristics, starting from the broadest category to the most specific. Taxonomy typically includes several hierarchical levels: domain, kingdom, phylum, class, order, family, genus, and species. This organized method not only aids in the identification and naming of organisms but also helps in understanding the relationships between different life forms, reflecting their evolutionary lineage and traits, thus contributing to the field of biology.