是一分類系統的科學；分類的原理與法則。The science of classification; the laws and principles covering classification of objects.

是一分類系統，特別指動物與植物的分門別類。Classification, especially of animals and plants into phyla, species, etc.”

分類學: 一種分類的科學與實務。 Taxonomy is the practice and science of classification. The word finds its roots in the Greek τάξις, taxis (meaning 'order' or 'arrangement') and νόμος, nomos (meaning 'law' or 'science'). Taxonomy uses taxonomic units, known as taxa (singular taxon).

分類法: 一種特定的分類法或分類系統。這種分類法依階層架構排列，通常類別間具有「上-下位階」的關係，或稱為「概括-具體關係」、「父-子關係」等。上位類別的屬性會繼承到下位的類別。 In addition, the word is also used as a count noun: a taxonomy, or taxonomic scheme, is a particular classification (“the taxonomy of …”), arranged in a hierarchical structure. Typically this is organized by supertype-subtype relationships, also called generalization-specialization relationships, or less formally, parent-child relationships. In such an inheritance relationship, the subtype by definition has the same properties, behaviors, and constraints as the supertype plus one or more additional properties, behaviors, or constraints. For example: car is a subtype of vehicle, so any car is also a vehicle, but not every vehicle is a car. Therefore a type needs to satisfy more constraints to be a car than to be a vehicle. Another example: any shirt is also a piece of clothing, but not every piece of clothing is a shirt. Hence, a type must satisfy more parameters to be a shirt than to be a piece of clothing