Devices derived from transporter technology to dematerialize matter and then reconstitute it in another form.

Replicators, in use since the early 24th century, are most commonly used as food dispensers aboard Federation starships. The menu is only limited by the programming, as opposed to the days of carrying natural or reconstituted foodstuffs with delivery by special turbolifts or transporters.

Generally replicated food and "natural" food taste the same, though some people claim to be able to detect a difference.  For instance, Captain Picard kept real caviar stored for special occasions since he felt replicated caviar was inferior to the real thing.