Investigators confirmed they have recovered a cockpit voice recorder and a flight-data recorder from American Eagle Flight 5342, which will undergo analysis.

The so-called “black box” is one of the most important pieces of forensic evidence following a plane crash. There are actually two of these remarkably sturdy devices.

What is a black box, what can it tell us, and have the data recorders been found from Flight 5342 and the Army's Blackhawk?