welfare worker vs social worker

welfare worker and social worker both are nouns.

Word	Noun	Adjective	Verb	Adverb
welfare worker	Yes	No	No	No
social worker	Yes	No	No	No

As nouns, welfare worker and social worker are synonyms defined as:

welfare worker and social worker: someone employed to provide social services (especially to the disadvantaged)

Other synonyms of welfare worker include caseworker.

welfare worker (noun)	social worker (noun)
someone employed to provide social services (especially to the disadvantaged)	someone employed to provide social services (especially to the disadvantaged)