A joke is a short story or ironic depiction of a situation communicated with the intent of being humorous. A practical joke or prank differs from a spoken one in that the humor is mainly physical rather than verbal (e.g. placing salt in the sugar bowl, or more cruel "jokes" such that involve destruction of another's property).
Jokes are typically for the entertainment of friends and onlookers. The desired response is generally laughter, although loud groans of revealed stupidity are also a common response to some "dumb" jokes, such as puns and shaggy dog stories.