What is meant by binomial nomenclature and what are its basic rules?

Scientific nomenclature of a species must have, at least, two names: one that classifies it as genus and the other that identifies it as species. The name related to genus is the first and must start in uppercase, the other following names must be written in lowercase. Besides this rule, scientific names of species must stand out and be written either in italics or underlined or still bolded or among quotation marks.

For example, the scientific name of the human species is "Homo sapiens", showing that it belongs to the genus Homo.