Blu-ray is a disc format that displays high definition video and stores large amount of data. It is the successor to DVD. The name comes from the fact that a blue laser reads from and writes to the disc rather than the red laser of DVD players.
The storage capacity of a Blu-ray disc is large (up to 50GB). To play a Blu-ray disc you would need a Blu-ray disc player (BDP) and will not play on your standard CD and DVD players as those players lack the blue laser required to read the discs. However, a BDP can generally play the CD and DVD formats.