In some forms of Linnean system of hierarchical classification, a kingdom is the highest grouping of similar organisms. Alternatively, the hierarchical grade between Phylum and Domain.
A kingdom contains one or more phyla (plural of phylum). The number of Kingdoms differs according to the type of classification used; often Kingdoms are in turn grouped into Domains, and Domains into Origins (each separate development of life from inorganic matter constitutes a distinct Origin). When Domains and strict cladistics are not considered, Terragen Life is traditionally divided into five kingdoms: Animalia, Plantae, Fungi, Protista (protozoans and eucaryotic algae), and Monera (bacteria blue-green algae).