Fantasy is the use of imagination to picture things that don't exist in the real world, or a story built around magical, impossible, or make-believe elements. When you daydream about having superpowers or imagine what it would be like to ride a dragon, you're engaging in fantasy.

In literature and entertainment, fantasy describes stories set in imaginary worlds where magic works, mythical creatures exist, and the normal rules of reality don't apply. The Chronicles of Narnia, The Hobbit, and Percy Jackson are all fantasy novels. These stories might include wizards, talking animals, or quests to save magical kingdoms.

Fantasy differs from science fiction in an important way: science fiction imagines future technology or space exploration that might theoretically become possible, while fantasy embraces the purely magical and impossible. A story about colonizing Mars is science fiction, but a story about a magic ring that makes you invisible is fantasy.

The word can also describe unrealistic hopes or expectations. If someone thinks they'll become a professional athlete without practicing, that's just a fantasy. When used this way, it suggests the person isn't being realistic about what's actually required.