What is the difference between DVD and Blu-Ray?

DVD discs come in two capacities:
Single layer can hold up to 4.7 gig of data.
Double layer can hold up to 8.5 gig of data.
Video format that can be played on a "regular" DVD player is a highly compressed VOB format. This is standard definition video.
A red laser is used to read and write data on the DVD.
A regular DVD player cannot play Blue Ray discs.

Blue Ray discs come in different sizes - most common can hold up to 25 gig and 50 gig.
Video format that can be played in a Blue Ray player is MTS.
There can be standard definition or high definition video in the MTS file.
A blue laser is used to read/write data on the Blue Ray disc.
A Blue Ray player can usually play a DVD with a properly installed VOB file.

Blu-Ray was invented for full high def. Mainly, though, it was a ploy by the industry to get consumers to adopt the next, newest technology and pilfer their pockets. It has worked so well in the past, so, why not?

In simple terms for the average user, Blu-Ray offers higher quality sound and picture than DVD. Unlike DVD, Blu-Ray is high definition and the difference is significant on a modern HDTV.

For data storage on a computer with Blu Ray capability, the capacity is much higher than DVD.

Both the quality of sound and video is hugely improved with Blu-Ray. Think of it as what's the difference between VHS and DVD, it's the same but DVD is Standard Definition and Blu-Ray is High Definition

Blu ray has a better quality picture on screen

They're optical storage discs and are of the same size format.

But DVDs have a maximum data capacity of 4.7GB and Blu-Ray discs have a far higher 25GB capacity. Dual layer discs ouch that to 50GB and there are some triple and quadruple layer discs as well.

Just as DVD evolved from CD and can also play CD, Blu-Ray evolved from DVD and can usually play DVD and CD. The "usually" is due to the fact that Blu-Ray uses a different shorter wavelength "blue" (it's actually violet) laser to read discs but needs to include a conventional red laser to read DVD and CD. Some dedicated Blu-Ray machines omit the extra laser head and after a couple of years usage it's not unusual to find that one of the two heads has failed on a dual-head player.

The main reason for all the additional data capacity on a Blu-Ray disc is to carry enough data for high definition video. With upgrades to the internal electronics they're also capable of providing that extra data fast enough to work with 3D TVs.

about 20 dollars

Bluray looks better. But you will need a bluray player and hdtv to see it.
Bluray players can play dvds.

Dvd players cannot play blurays.

Trolls ask generic questions like these.

If you really want information - you need to tell us WHY you want to know. Then we can phrase a good answer for you.

https://en.wikipedia.org/wiki/Comparison_of_high_definition_optical_disc_formats

DVD stores 4.7GB or 8.5GB dual-layer. BluRay stores 25GB single layer, 50GB dual layer, 100GB triple layer, and 128GB quadruple layer. For movies it means you can fit more HD content on a single BluRay disc rather than split up an HD movie across multiple DVDs. You can store HD content on a DVD, just not very much.

Blu ray has a better quality picture on screen

Go and buy one of each, you will soon know the main answer!

Blu-ray or Blu-ray Disc (BD, BRD) is a digital optical disc data storage format. It was designed to supersede the DVD format, in that it is capable of storing high-definition video resolution (1080p). The plastic disc is 120 mm in diameter and 1.2 mm thick, the same size as DVDs and CDs.[5] Conventional (pre-BD-XL) Blu-ray Discs contain 25 GB per layer, with dual layer discs (50 GB) being the industry standard for feature-length video discs. Triple-layer discs (100 GB) and quadruple-layers (128 GB) are available for BD-XL re-writer drives.
DVD ( "digital versatile disc"[4][5] or "digital video disc"[6]) is a digital optical disc storage format invented and developed by Philips, Sony, Toshiba, and Panasonic in 1995. The medium can store any kind of digital data and is widely used for software and other computer files as well as video programs watched using DVD players. DVDs offer higher storage capacity than compact discs while having the same dimensions.

there is a huge

Blu-Ray holds far more data . Thus far better quality ...

data storage capacity

Blu-ray is higher definition, but you would need a Blu-ray Player to play discs. DVD can be played in your average DVD player.

Storage

i don't know

Consider difference of CD and DVD, and you effectively answer your question. The meta-physical difference of these two differences are time and how we consume media; namely streaming rather than renting a disc. Downloading apps instead of buying compilation.

There is a huge difference between Blu-Ray and DVD. A Blu-ray player is just a higher-definition player, and will give a more detailed picture when playing a Blu-Ray DVD. But DVD is Standard Definition than Blu-ray. Dvd players cannot play Blu-Rays.

In simple terms for the average user, Blu-Ray offers higher quality sound and picture than DVD. Unlike DVD, Blu-Ray is high definition and the difference is significant on a modern HDTV.

For data storage on a computer with Blu Ray capability, the capacity is much higher than DVD

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