A genie is a mythological spirit. In stories, most genies are described as magical beings that live inside lamps or bottles and grant people's wishes.
The word genie comes from the French génie, a word that was coined for the French translation of the book Arabian Nights and comes from the Arabic jinni. Genies were a staple of ancient Arabian myths, and later of Islamic folktales. If you've ever seen the movie Aladdin, you know the popular version of a genie, who appears to grant wishes after being summoned from an oil lamp.