Carolus Linnaeus invented a classification system for living things. His naming system was called binomial nomenclature. This naming system gives each organism two names: a genus name and a species name.
Before Linnaeus, scientists put organisms into different categories based on their observable characteristics. Those classification systems did not account for similarities between species or show relationships between organisms. Linnaeus placed species into successively higher and more inclusive groups such as orders, classes and kingdoms.
With binomial nomenclature, each organism became known by two Latin or Latin-derived names. The first name is capitalized and referred to an organism's genus. The second part of the name, which is not capitalized, is the species name, which means nothing by itself; with the genus name in front, the two words become an organism's unique designation.