Blu-Ray is a different technology from DVD. Therefore, a Blu-Ray disc will not function properly in your standard DVD player. A DVD will work on a Blu-Ray player, but it will not be as good of quality as a Blu-Ray disc on a Blu-Ray player.
No. Keep in mind that the DVD was made prior to the Blu ray. But the all Blu Ray disc player can play the DVD along with CD. The player will display on top or front on what format it can play. Hope this will help you out.