posting vs poster

posting and poster both are nouns.

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

As nouns, posting and poster are synonyms defined as:

Other synonyms of posting include bill, card, notice, placard.

posting (noun)	poster (noun)
the transmission of a letter	a horse kept at an inn or post house for use by mail carriers or for rent to travelers
a sign posted in a public place as an advertisement	a sign posted in a public place as an advertisement
(bookkeeping) a listing on the company's records	someone who pastes up bills or placards on walls or billboards