Taxonomy (from ancient Greek τάξις taxis, arrangement, and νομία nomia, method) is the academic discipline of defining groups of biological organisms on the basis of shared characteristics and giving names to those groups. Each group is given a rank and groups of a given rank can be aggregated to form a super group of higher rank and thus create a hierarchical classification. The groups created through this process are referred to as taxa (singular taxon). An example of a modern classification is the one published in 2009 by the Angiosperm Phylogeny Group for all living flowering plant families (the APG III system).
Read more about Taxonomy: Definitions, Application, Taxonomic Descriptions, Classifying Organisms, Non-biological Taxonomies