written language vs written communication

written language and written communication both are nouns.

Word	Noun	Adjective	Verb	Adverb
written language	Yes	No	No	No
written communication	Yes	No	No	No

As nouns, written language and written communication are synonyms defined as:

written language and written communication: communication by means of written symbols (either printed or handwritten)

Other synonyms of written language include black and white.

written language (noun)	written communication (noun)
communication by means of written symbols (either printed or handwritten)	communication by means of written symbols (either printed or handwritten)