What is the difference between Blu-ray Disc, DVD & CD?

Last Update date : Oct 12. 2020

Just as DVD meant a 5 to 10 times increase in storage capacity compared to CD, Blu-ray Disc will increase DVD capacity by 5 to 10 times. This is due, among other reasons, to the usage of a blue instead of a red laser and improved lens specifications, allowing for a much smaller focus laser beam which enables the recording of much smaller and higher density pits on the disc.

 

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Below listed are major differences between a DVD & a Blu-Ray Disc :

 
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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

0.6

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

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