promoter vs barker

promoter and barker both are nouns.

Word	Noun	Adjective	Verb	Adverb
promoter	Yes	No	No	No
barker	Yes	No	No	No

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

promoter: someone who is an active supporter and advocate
barker: someone who stands in front of a show (as at a carnival) and gives a loud colorful sales talk to potential customers

promoter (noun)	barker (noun)
someone who is an active supporter and advocate	informal terms for dogs
a sponsor who books and stages public entertainments	someone who stands in front of a show (as at a carnival) and gives a loud colorful sales talk to potential customers