computer system vs automatic data processing system

computer system and automatic data processing system both are nouns.

Word	Noun	Adjective	Verb	Adverb
computer system	Yes	No	No	No
automatic data processing system	Yes	No	No	No

As nouns, computer system and automatic data processing system are synonyms defined as:

computer system and automatic data processing system: a system of one or more computers and associated software with common storage

Other synonyms of computer system include ADP system, ADPS, computing system.

computer system (noun)	automatic data processing system (noun)
a system of one or more computers and associated software with common storage	a system of one or more computers and associated software with common storage