electronic information service vs on-line database

electronic information service and on-line database both are nouns.

Word	Noun	Adjective	Verb	Adverb
electronic information service	Yes	No	No	No
on-line database	Yes	No	No	No

As nouns, electronic information service and on-line database are synonyms defined as:

electronic information service and on-line database: (computer science) a database that can be accessed by computers

Other synonyms of electronic information service include computer database, electronic database.

electronic information service (noun)	on-line database (noun)
(computer science) a database that can be accessed by computers	(computer science) a database that can be accessed by computers