information processing vs information science

information processing and information science both are nouns.

Word	Noun	Adjective	Verb	Adverb
information processing	Yes	No	No	No
information science	Yes	No	No	No

As nouns, information processing and information science are synonyms defined as:

information processing and information science: the sciences concerned with gathering, manipulating, storing, retrieving, and classifying recorded information

Other synonyms of information processing include informatics, IP.

information processing (noun)	information science (noun)
the sciences concerned with gathering, manipulating, storing, retrieving, and classifying recorded information	the sciences concerned with gathering, manipulating, storing, retrieving, and classifying recorded information