Comic Conventions, Anime Conventions to just name a few offer many components depending on the event. Some have panels about your favorite Video Game, Movie or TV show with the celebrities and staff involved. Panels with Artists and/or creators of Comics and Graphic novels. Some conventions feature Cosplay and Cosplay contests, and you can also buy Comics, Rare Toys and Collectibles. There are also Conventions that have all of this content and so much more.
Cosplay: The practice of dressing up as a character from a movie, book, or video game, manga and anime.