The difference between Descriptivism and Formalism

Descriptivism as a noun (linguistics):

The practice of describing realistic forms, as opposed to prescribing idealistic norms, of linguistic usage.

Formalism as a noun:

Strict adherence to a given form of conduct, practice etc.

Formalism as a noun (computing):

One of several alternative computational paradigms for a given theory.

Formalism as a noun (literature):

An approach to interpretation and/or evaluation focused on the (usually linguistic) structure of a literary work rather than on the contexts of its origin or reception.

Formalism as a noun (music):

The tendency to elevate formal above expressive value in music, as in serialism.

Formalism as a noun (mathematics, physics):

A particular mathematical or scientific theory or description of a given state or effect.