What is a binomial nomenclature?

The method by which are given a scientific name.

Binomial nomenclature is a fancy way to say "a scientific two-word name." It uses the genus name, and then it uses the species name. For example, humans' scientific name is Homo sapiens. The genus is Homo, and the species is sapiens. You always should italicize the name, capitalize the first letter of the first word, and have the second word have no capital letters.