The categorization of living creatures is a multi-step process that incorporates a hierarchy of processes, with each step representing a rank or category. The category is called a taxonomic category because it is part of the larger taxonomic order.
The many types of creatures are grouped into seven obligatory categories, in which all living entities are classified either in descending order from kingdom to species or in ascending order from species to kingdom.
The hierarchical structure is seen below:
The kingdom is the highest and first category in the taxonomic structure. It is a collection of phyla or divisions that share relatively few basic traits.
Phylum (for animals) or Division (for plants): A higher level category than class. The term "phylum" refers to animals, whereas "division" refers to plants.
A class is defined as a collection of one or more linked orders.
Order: It is defined as a group of families, which means related families are kept in the same order.
Family: Following the genus, the next category is family. It consists of distinct groupings of related genera that have less commonalities than genus and species.
Genus: A genus is a group of closely related species that share many features with animals from different genera.
John Ray's basic unit of taxonomy is the species. It is described as a group of properly segregated and possibly interbreeding populations that are reproductively isolated and separated from other groupings of this type.