Difference between Blu-ray and DVD

Both Blue-Ray Disk and DVD are the optical type secondary storage devices used in computer systems. We are all familiar with DVDs, but Bluray discs are relatively new data storage devices. Blue ray discs give a better visual experience with high video resolution.

In this article, we will discuss the important differences between Blue-Ray Disc and DVD. But before going into the differences, let's start with some basic concepts of these two storage devices.

What is Blu-Ray?

BluRay Disk (BD) is an optical storage media used to store high definition (HD) video and other multimedia filed. BD uses shorter wavelength laser as compared to CD/DVD. This enables writing arm to focus more tightly on the disk and hence pack in more data. BDs can store up to 128 GB data.

Being a technology of data storage, it enables recording and playing high definition multimedia files and stores very large amount of data as compared to any other optical disc. BluRay Disc was developed by BDA (Blue-Ray Disc Association). Bluray disc offers capability of storing 1080p HD video files. Consequently, it gives more depth and a wide range of color shades in the video.

What is DVD Drive?

DVD for Digital Versatile Disc. DVD are optical devices that can store 15 times the data held by CDs. They are usually used to store rich multimedia files that need high storage capacity. DVDs also come in three varieties − readonly, recordable and rewritable.

DVD uses red laser technology for data read-write. A single layer DVD disc can store about 4.7 GB of data. DVD supports video resolution of 480p. The data transfer rate of a typical DVD is upto 54 Mbps. DVDs are comparatively cheaper than bluray discs.

Differences Blu-Ray and DVD

The following table compares and contrasts the features of Bluray discs and DVDs to highlight how they are different from each other −

Key Blu-Ray DVD
Definition Blu-ray disk uses blue optical ray which makes its name as Blu-ray. DVD stands for Digital Versatile Disk.
Size Blu-ray single layer size is 25 GB. DVD single layer size is 4.7 GB.
Recording Layer Recording layer or metal layer is close to reading mechanism's objective lens. Recording layer or metal layer is close to middle of the disk.
Pits Blu-ray have double layers of pits. DVD too have double layers of pits.
Space between loops Space between spiral loops is 0.30 micrometer in Blu-ray. Space between spiral loops is 0.74 micrometer in DVD.
Space between pits Space between pits is 0.15 micrometer in Blu-ray. Space between pits is 0.40 micrometer in DVD.
Correction code Picket Code is used as error correction code. RS-PC and EFMplus are used as error correction code.
Wavelength Wavelength of laser is 405nm. Wavelength of laser is 650nm.
Data Transfer Rate Data Transfer Rate is 36 Mb/Sec. Data Transfer Rate is 11 Mb/Sec.
Size Double Layer Size is 50 GB. Double Layer Size is 8.5 GB.
Numeric Aperture Numeric Aperture of Blu-ray is 0.8. Numeric Aperture of DVD is 0.6.
Thickness The thickness of a Blu-ray disc is 1.1 mm. The thickness of DVDs is 0.6 mm.


From the above discussion, it is clear that a bluray disc provides an optical storage medium with high quality and large space as compared to a DVD. It is also important to note that a DVD can be played in a DVD player and also in a bluray disc player, but a bluray disc can only be played in a bluray disc player.