smoker vs pipe smoker

smoker and pipe smoker both are nouns.

Word	Noun	Adjective	Verb	Adverb
smoker	Yes	No	No	No
pipe smoker	Yes	No	No	No

As nouns, pipe smoker is a hyponym of smoker; that is, pipe smoker is a word with a more specific, narrower meaning than smoker:

Other hyponyms of smoker include chain-smoker, cigarette smoker, cigar smoker.

smoker (noun)	pipe smoker (noun)
a passenger car for passengers who wish to smoke	a smoker who uses a pipe
a party for men only (or one considered suitable for men only)
a person who smokes tobacco