parallel processing vs multiprocessing

parallel processing and multiprocessing both are nouns.

Word	Noun	Adjective	Verb	Adverb
parallel processing	Yes	No	No	No
multiprocessing	Yes	No	No	No

As nouns, parallel processing and multiprocessing are synonyms defined as:

parallel processing and multiprocessing: simultaneous processing by two or more processing units

parallel processing (noun)	multiprocessing (noun)
simultaneous processing by two or more processing units	simultaneous processing by two or more processing units