What is trinomial nomenclature?

Trinomial nomenclature :
Sometimes a name consists of three words which indicate generic, specific and sub-specific categories. This is further followed by author’s name. Such a system of classification is called trinomial nomenclature, e.g. Columbia livia intermedia Strickland. Cauliflower and Cabbage are called Brassica oleracea var. botrytis and B. oleracea var. capitata, respectively.