The answer to the riddle "What has a neck but no head?" is a bottle. This is an example of a riddle that is found in the popular application "What the Riddles" featured on iTunes.
A riddle is a question or statement that has a double meaning and is used as a puzzle for others to solve. Sometimes a riddle can be funny, like a joke, and sometimes it can be difficult and thought provoking. In ancient Greece, riddles were by philosophers like Plato and Aristotle to display wit and intelligence. Shakespeare even used riddles in his famous writings and theater productions.