Ahmedabad Air India plane crash: What are black boxes? How do they work?

In modern aircraft, there is a Cockpit Voice Recorder and a Digital Flight Data Recorder; they are called black boxes even though they are painted with bright orange to ensure high visibility; black boxes hold the key to aircraft crash investigations

​In modern aircraft, there is a Cockpit Voice Recorder and a Digital Flight Data Recorder; they are called black boxes even though they are painted with bright orange to ensure high visibility; black boxes hold the key to aircraft crash investigations