(a) Polynomial system was found cumbersome. It mostly changed from scholar to scholar. So, Carolus Linnaeus (1758) devised a shorthand designation, binomial (L.bi = two; nomen = name),for each species.
(b) The bionomial system became common. The scientific name of mango is Mangifera indica. There are two words in Latin. Mangifera shows the Genus and indica the species. Likewise, the honeybee is known as Apis mellifera.
(c) Every scientific name has a first word for genus followed by a second word denoting the species. Hence, binomial nomenclature is the system of scientific naming of an organism using 'genus' as the first part and 'species' as the second part as stated by Carolus Linnaeus.