In biology, a phylum (/ˈfaɪləm/ ; plural: phyla) is a taxonomic rank below kingdom and above class.Traditionally, in botany the term division was used instead of phylum, although from 1993 the International Code of Nomenclature for algae, fungi, and plants accepted the designation phylum.n biology, a phylum (/ˈfaɪləm/ ; plural: phyla) is a taxonomic rank below kingdom and above class.