It is rare to find a clunky VHS tape in someone’s house nowadays. Even if a VHS is still underneath the couch, chances are it has already been converted to DVD for better quality. The DVD was released in 1997, but now the standard-resolution DVD is competing with the High-Definition DVD and the latest technology, the Blu-Ray DVD.
What exactly are HD DVD and Blu-ray?
The HD DVD shows 6x better picture quality by replacing the standard red laser used by regular DVD players with a blue 
laser. This blue laser scans data using shorter wavelengths and stores more on discs. What does shorter wavelengths mean? Standard DVD players have more space between the laser and disc, suffering more diffraction that limits their ability to focus tightly on the surface. So the standard DVD players provide for less precision which means less resolution and storage. The HD DVD discs store up to 15GB (4+ hours) on single-layer and 30GB (8+ hours) on double-layer discs.
The standard DVD can only hold up to 4.7GB (2+ hours) or 8.5GB (4+ hours) on double-layer discs. This quick scan and storage allows for eye-popping graphics and up to 7.1 clear surround sound. This is better sound than most movie theatres. HD DVD players are backwards-compatible, meaning they can also play standard DVDs also.
The Blu-ray technology improves upon the HD DVD technology by using the same laser, but uses a different disc surface. The surface is .25mm less and allows for even more precision from the HD DVD resolution. Also, it can hold up to 25GB (6+ hours) on single-layer discs and 50GB (13+ hours) on double-layer discs. It is backwards-compatible to also play HD DVDs and standard DVDs.
So, if you’re considering buying your next DVD player, you should probably consider the Blu-ray products to avoid becoming obsolete in a few years. Remember, that along with buying the Blu-ray player, you’ll need to buy the associated cabling for the player and TV. And, of course, you’ll need to have a Blu-ray TV to take advantage of this supreme technology. Once you have the correct equipment, then the hard part is figuring out which movies you’d like to play.