abbreviation vs descriptor

abbreviation and descriptor both are nouns.

Word	Noun	Adjective	Verb	Adverb
abbreviation	Yes	No	No	No
descriptor	Yes	No	No	No

As nouns, descriptor is a hypernym of abbreviation; that is, descriptor is a word with a broader meaning than abbreviation:

abbreviation: a shortened form of a word or phrase
descriptor: the phonological or orthographic sound or appearance of a word that can be used to describe or identify something

Other hypernyms of abbreviation include form, signifier, word form.

abbreviation (noun)	descriptor (noun)
shortening something by omitting parts of it	a piece of stored information that is used to identify an item in an information storage and retrieval system
a shortened form of a word or phrase	the phonological or orthographic sound or appearance of a word that can be used to describe or identify something