DVD Vs. Blu-Ray: What's The Difference?

Physical media has largely been replaced with digital alternatives now. Streaming services dominate the movie and television markets, while platforms such as Steam or console-specific e-stores are used for games. This is a relatively recent phenomenon, made possible only with improved global internet availability and better methods of online compression. Before this, if you wanted to watch anything at your leisure, you had to own a physical disc or a VHS tape.

Digital Versatile Discs (DVDs) and Blu-ray discs are the most recent major format of physical media before the standard started dying out. Both record data in binary – in values of zeros and ones. To do this, each disc has an outer reflective layer with precise, tiny dips in it. When your DVD or Blu-ray player's laser reads the disc, it reflects only off of this reflective layer and not where there's a dip. Each reflection represents a one in binary, and each absence of a reflection represents a zero.

DVDs use either infrared or red light for this, whereas Blu-ray discs, as the name suggests, use blue-violet light. Since blue-violet light has a much shorter wavelength than red light, it can read smaller, more precise gaps within the disc. This is why Blu-ray discs can store much more data than DVDs, even if they're the same physical size. The companies behind the two formats differ as well. Sony and Philips are part of the forums behind both, but Toshiba and Time Warner only had a hand in DVD, while industry giants like Panasonic and LG, among others, contributed to Blu-ray.

Blu-ray discs weren't a direct successor to the DVD. They were a rival format that existed alongside traditional DVDs for a while. Blu-ray was an improvement over the base DVD across the board. A traditional DVD could hold a maximum of 4.7GB of data on a single layer since it didn't use blue-violet light, while a Blu-ray disc has a base capacity of up to 25 GB. Similarly, while DVDs only supported 480p resolutions, Blu-ray discs could offer 1080p instead.

This is only when we compare Blu-ray discs with the base DVD format that first hit the markets in 1996, though. Why Blu-ray replaced DVD is more nuanced than that, as the later released HD DVDs (High Density Digital Versatile Discs) had most of the advantages that came with Blu-ray. They used blue-violet light, could hold up to 15GB of data per layer, and offered the same 1080p resolution as Blu-ray discs.

One obvious reason Blu-ray discs won is the increased capacity. 25GB compared to 15GB already seems like a big difference, but the reality was even more significant. Full-HD movies and large, open-world games often required upwards of 80GB, something that neither format supported. To combat this, both technologies opted for multiple layers on the discs, essentially doubling or tripling the capacity. A dual-layer disc could hold up to 50GB, while a triple-layer disc could hold 75GB, but an HD DVD disc could only hold 30GB or 45GB, even with these extra layers.

Neither DVDs nor Blu-rays are especially popular today. Streaming services are much more convenient for the average user. While a single movie can cost around $25 on Blu-ray, you can get a Netflix subscription from $8.99 a month and enjoy thousands of different movies and series, both old and new. Add to that how expensive a 4K Blu-ray player can be, and it makes complete sense why most prefer streaming.

However, this doesn't mean that streaming is superior in every respect. Even if they seem obsolete, Blu-rays offer better visuals than any online streaming platform out there. Standard Blu-ray discs have a 1080p resolution, the same as Netflix's standard tier. But the more premium Ultra HD Blu-ray standard offers 4K resolution (thanks to up to 100GB of storage), matching Netflix's more premium subscription plans. The numbers seem the same, but resolution isn't all there is to what makes something look good on your screen.

The main reason Blu-ray offers better visuals than streaming even at the same resolution is because of bitrate and compression. While resolution refers to how many pixels are shown at any given time, bitrate refers to how much data is processed each second. Netflix gives you a maximum bitrate of 20 megabits per second (Mbps) when you're streaming in 4K. The standard Blu-ray disc offers significantly more than this, often up to 40 Mbps, and Ultra HD Blu-ray discs completely demolish streaming with bitrates upwards of 100 Mbps. This makes Blu-rays the optimal choice for cinephiles wanting the best visual experience, and is the reason why new releases still come out on a seemingly obsolete medium.