Type
Type has historically had the following uses:
- In the development of printing, type refers to the metal forms of the letters used in typesetting. See, for example, typewriter.
- In biology, a type is the specimen or specimens upon which an original species description is based.
- In computing, the datatype (sometimes called simply 'type') of an object depends on its classifier. In object-oriented programming, it became useful to distinguish an abstract data type from an 'implemented datatype'.
- In the decades of the 1900s and 1910s, in philosophy, Bertrand Russell used his Theory of Types to further discuss the mapping of mathematics to logic. See Principia Mathematica
- In set theory and musical set theory, see equivalence class.