Bookmark and Share

The Difference Between Blu-ray and DVD

With the popularity of Blu-ray, many people still can't tell Blu-ray from DVD.

 

If you do not know the difference between Blu-ray and DVD exactly, you can find your answer from the table below.

 

Parameters
Blu-ray
DVD
Storage capacity
25GB (single-layer)
4.7GB (single-layer)
 
50GB (dual-layer)
8.5GB (dual-layer)
Laser wavelength
405nm (blue laser)
650nm (red laser)
Numerical aperture (NA)
0.85
0.60
Disc diameter
120mm
120mm
Disc thickness
1.2mm
1.2mm
Protection layer
0.1mm
0.6mm
Hard coating
Yes
No
Track pitch
0.32μm
0.74μm
Data transfer rate (data)
36.0Mbps (1x)
11.08Mbps (1x)
Data transfer rate (video/audio)
54.0Mbps (1.5x)
10.08Mbps (<1x)
Video resolution (max)
1920×1080 (1080p)
720×480/720×576 (480i/576i)
Video bit rate (max)
40.0Mbps
9.8Mbps
Video codecs
MPEG-2
MPEG-2
 
MPEG-4 AVC
-
 
SMPTE VC-1
-
Audio codecs
Linear PCM
Linear PCM
 
Dolby Digital
Dolby Digital
 
Dolby Digital Plus
DTS Digital Surround
 
Dolby TrueHD
-
 
DTS Digital Surround
-
 
DTS-HD
-
Interactivity
BD-J
DVD-Video

 

Blu-Ray uses a blue-violet laser as opposed to the red laser used on DVDs. This allows Blu-Ray discs to hold a lot more information on them than DVDs.

 

This increase in the amount of information that can be stored on a disc allows you to put High-Definition movies on a disc and not run out of space, since the average HD movie will take up about 15-20 GB of space.

 

If you have not seen an HD movie yet I would suggest stopping by your local Best Buy or Circuit City and looking at a Blu-Ray display. The images are sharper, brighter, and more detailed than any DVD movie. What manufacturers are trying to do is make the movie look as close to what you see in a real theater as possible, except for its a tenth the size and in your home.

 

Blu-Rays cannot be played in a traditional DVD player, which means that you will eventually have to buy a blu-ray player. However, all blu-ray players can play DVDs, and they upscale the images to look better on an HD screen, up to 1080p.

 

So, while you will have to get a new Blu-Ray player to play HD movies, you can still see all of your current DVDs on the same player, and they'll be enhanced.

 

In essence, Blu-Ray will replace DVD just as DVD replaced VHS and the CD replaced the Casette Tape.