Taxonomy's the practice and science of classification. The word finds its roots in the Greek τάξις, taxis (meaning 'order', 'arrangement') and νόμος, nomos ('law' or 'science'). Taxonomy uses taxonomic units, known as taxa (singular taxon). In addition, the word's also used as a count noun: a taxonomy, or taxonomic scheme,'s a particular classification ("the taxonomy of ..."), arranged in a hierarchical structure. Typically this's organised by s… (More on Taxonomy)