information processing system vs computer

information processing system and computer both are nouns.

Word	Noun	Adjective	Verb	Adverb
information processing system	Yes	No	No	No
computer	Yes	No	No	No

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

information processing system and computer: a machine for performing calculations automatically

Other synonyms of information processing system include computing device, computing machine, data processor, electronic computer.

information processing system (noun)	computer (noun)
a machine for performing calculations automatically	a machine for performing calculations automatically
	an expert at calculation (or at operating calculating machines)