What are the main features of the binomial system in naming organisms? : )

The binomial system of nomenclature  is a two- part scientific naming system. There are several rules to follow when using the binomial system:  firstly, the genus comes first and begins with a capital letter, secondly the species name follows and begins with a lower case letter. Thirdly, both names are italicised and sometimes underlined. The ranks or categories of genus and species have significance because they form the basis of the binomial system. For example Homo (genus) sapiens (species) (humans) and Macropus (genus) giganteus (species) (Eastern grey kangaroo).  The classification category, species, is the lowest rank in the five kingdom system to which all organisms must be classified.