Conlangs are sometimes divided into three groups:
- artlangs, those devised for artistic purposes -- either per se, or for use in fiction.
Really for artistic purposes? Its purpose seems to have been IAL, the "esthetic" side - the musical version -- was partly practical (tone carries farther than words and is easier to pick out in a noisy environment) and partly either a bad joke or a misunderstanding of the claim that music is the universal language (which is clearly false even when rightly understood).
- engelangs (engineered languages), those devised according to some sort of objective principles; loglangs are engelangs based on predicate logic.
- auxlangs, those devised principally as IALs
- a posteriori
- a priori
These categories are of course overlapping.