The characteristics of a person or thing are the qualities or features that belong to them and make them recognizable.A quality or feature that is characteristic of someone or something is one which is often seen in them and seems typical of them.
Classification in biology means the arrangement of animals and plants in taxonomic groups according to their observed similarities (including at least kingdom and phylum in animals, division in plants, and class, order, family, genus, and species).
Classification is a general process related to categorization, the process in which ideas and objects are recognized, differentiated, and understood.