With the advent of modern technologies, it has become customary to discard the old in favour of the new. However, in the case of Blu-ray discs and DVDs, both still hold more or less equal importance in the optical disc market.
DVDs are primarily used for standard-definition videos while Blu-ray discs are for high-definition videos. Although both discs are similar in terms of shape and size, they differ in various other factors, like storage capacity, image resolution, player compatibility, laser technology etc.
Neo-Online highlights the major differences between the two below.
Storage Capacity
The biggest difference between a DVD and Blu-ray disc is, of course, their storage capacities. A standard DVD can hold about 4.7 GB of data (15 times the data that could be stored in CDs), which is enough for a film. However, if a film is any longer than 2 hours, a double-layer DVD would be needed, which can store almost 9 GB.
On the other hand, a high-quality Blu-ray disc can be used to store about 50 GB of data, with the BD-XL having a capacity of up to 128 GB. It is capable of supporting high-definition videos (720p and 1080p) and even ultra high-definition resolution videos (2160p). While it is usually used to store films, it can also be used for video games because of its massive capacity.
Image Resolution
Blu-ray is made for HD, and the Ultra HD Blu-ray (launched in 2016) enabled developers to encode data on the discs in 4k resolution — making Blu-ray discs the clear winner in comparison to DVDs.
Audio Quality
Similarly, Blu-ray discs have a more crisp sound quality than DVDs. They support audio formats such as Dolby Atmos, Dolby TrueHD, DTS:X and DTS-HD Master Audio.
Laser Technology
DVD and Blu-ray players use lasers to read discs. The DVD laser is a red laser of 650-nanometer wavelength, whereas the Blu-ray laser is blue and works on 405-nanometer wavelengths. The latter allows data to be stored at a greater density.
Disc Construction
Although not visible to the naked eye, the grooves on Blu-ray discs are thinner and more clustered together, so that the blue laser can read the data in a more precise manner. This is why they are able to pack in large amounts of data.
The hard coating of the discs also makes them more scratch-resistant than DVDs.
Player Compatibility
A Blu-ray disc cannot be played on DVD players as these do not have the blue-violet laser that could read them. On the other hand, Blu-ray players can play DVDs. They can also play streaming content from the internet and devices like flash drives. Analog connections were removed from Blu-ray disc players in 2013, and replaced with an HDMI connection.
In a Nutshell
The following table shows a summary of the main differences between DVDs and Blu-ray discs.
| DVDs | Blu-Ray Discs | |
| Usage | Standard-definition videos | High-definition videos; high-definition audios; data storage; Playstation 3 & 4 games; Xbox One games; 3D |
| Storage Capacity |
|
|
| Video Quality | 720 x 480 resolution | 1920 x 1080 resolution |
| Data Transfer Rate | 11 MB/s | 36 MB/s |
| Thickness | 0.6 mm | 1.1. mm |
| Laser Technology | Red laser (650 nm) | Blue laser (405 nm) |
| 3D | Does not support 3D | Supports 3D |
Even though Blu-ray discs are a notch higher than DVDs due to improved quality and storage capacity, DVDs do come with their own set of benefits. For instance, they are much cheaper, and more variety may be available in DVDs than Blu-ray. As long as you have quality DVDs, you don’t need to be updated with the latest technology to enjoy your favourite movie.