Poster

noun
  1. A large printed picture, notice, or advertisement displayed in a public place. noun
    The movie poster was displayed outside the theater.
    She decorated her room with posters of her favorite bands.
  2. A person who posts something online, such as a message, comment, or image. noun
    The poster of the controversial comment received a lot of backlash.
    As an active poster on the forum, she often shared helpful advice.