poster vs worker

poster and worker both are nouns.

Word	Noun	Adjective	Verb	Adverb
poster	Yes	No	No	No
worker	Yes	No	No	No

As nouns, worker is a hypernym of poster; that is, worker is a word with a broader meaning than poster:

poster (noun)	worker (noun)
a horse kept at an inn or post house for use by mail carriers or for rent to travelers	sterile member of a colony of social insects that forages for food and cares for the larvae
a sign posted in a public place as an advertisement	a person who works at a specific occupation
someone who pastes up bills or placards on walls or billboards	a member of the working class (not necessarily employed)
	a person who acts and gets things done