Constructed language
A constructed language, also called an artificial or planned language or a conlang,[1] is a language created by a person or group of people. It is created as a whole, not evolving naturally by being spoken by a group of people over time.
Constructed languages can be further grouped into engineered, auxiliary and artistic languages.
Engineered languages are created for the scientific study of and experimentation with language, or logic and philosophy.
Auxiliary languages are languages created for (international) communication. Well known auxiliary languages are Esperanto, Ido, and Interlingua. The first well-known one was Volapük, but the first one was Lingua Ignota.
Artistic languages are languages created for aesthetics; languages created for fictional settings mostly also fall in this category. Well-known artistic languages include J.R.R. Tolkien's languages and Star Trek's Klingon.
An a priori language is created without reference to natural languages, while an a posteriori language is based on natural languages. Esperanto is an example of an a posteriori language.[2]