Optical media, referring to CDs, DVDs, and BDs, have played a vital role in computing over the years. After the floppy disk became obsolete, CD drives became mainstream in computers. It came to a point where most software was distributed on CDs. Then came the DVD, which quickly replaced the CD in many ways and had its drives implemented in most computers. The third generation of optical media, the Blu-Ray disc, might not be as well-used. Use of all three generations is declining overall. How can the technology world survive without optical media? To answer this question, let's look at the different optical media types.

The Compact Disc

In 1982, the audio CD was released to the public. Just like all new technologies, it had a slow start. Relatively quickly, though, it overtook the gramophone record by becoming the mainstream method of music distribution. It held 74 minutes of audio and was quite convenient in comparison to its predecessor. In 1985, the CD-ROM, or Read Only Memory, brought optical media into the computing world. Consecutively, the CD-R, or Recordable Compact Disc, was developed in 1990. As time passed, CD drives became increasingly common in computers; they became standard by the early 1990s. It swiftly became the prefered method of software distribution. It was the primary cause of the decline of the floppy disk, which held a mere 1.5 MB versus the CD's 650 MB (later increased to 700 MB). The enlarged capacity encouraged more powerful apps and games. Also recall that they predated USB flash drives and high-speed Internet. After recordable drives became widespread, it was virtually the sole method of file transportation. Never before have people been able to easily transport computer-readable photos and videos. CD use flourished in both audio and data variants for a while. The natural successors to the audio CD was digital music on iPods or Mp3 players. Currently, digital album sales are on the verge of surpassing CD sales, and that's even excluding digital singles. CD-ROMs are hardly used to distribute modern software. The capacity of a CD often isn't enough, so a DVD is used. Conversely, it's typically more convenient to download a smaller file. [caption id="attachment_560" align="alignright" width="253"] CD under an electron microscope, showing the pits and lands of the data track. Credit: Thctamm, Wikimedia Commons[/caption]

The Digital Versatile Disc

Originally the digital video disc, but renamed to the digital versatile disc, the DVD was the second generation of optical media. Introduced to the United States in 1997, the new technology caught on fairly quickly. It is controversial as to how the video and audio quality on DVDs compared to those on a VHS tapes. One thing's for certain though: they're far more convenient, mainly thanks to their improved features, like not having to be rewound. By mid-2003, DVD sales and rentals surpassed those of VHS tapes, the video DVD's predecessor. In the following two years, many major retailers purged their supply of VHS tapes therefore making DVDs the new standard. Once again, DVDs also began making their way into the computer world. The DVD-ROM partly succeeded the CD-ROM as the prefered method of software distribution. Its capacity is greater than six CDs, due to its smaller track winding, totalling 4.7 GB. Content smaller than 700 MB continued to be distributed on CDs, as they're more cost-efficient, and DVD drives are backwards compatible with them. Additionally, recordable DVDs, or DVD-R, caught on. They became widely used for home movies or as flash drives. Over time, discs similar to the DVD-R became popular, like DVD+R and DVD±RW. At one point, almost every new computer contained a DVD drive, due to becoming required to install most software and their sheer popularity. [caption id="attachment_565" align="alignleft" width="350"] Comparison of properties of the CD, DVD, and BD, including the data track size. Credit: Cmglee, Wikimedia Commons[/caption]

The Blu-Ray Disc

The third generation of optical media was the BD, meaning Blu-Ray disc. It's named after the blue laser in a BD reader, rather than a red or infrared one. This high-power laser is needed to successfully read the BD's even smaller data track. Really, the BD was designed to succeed the DVD. As expected, it is commonly used for video distribution. Though it uses different codecs, the BD is mainly set apart since it can store full HD video. This allows for several times more detailed of a picture than the now-inferior DVD. However, the Blu-Ray has not fully taken over the DVD yet, as indicated by the fact that most new movies are available in both formats. BDs are a premium when compared to a DVD, and at this point, not everyone has upgraded their DVD player to a Blu-Ray player. The BD is also available in recordable formats, like BD-R, and can therefore be used in computers, similar to its predecessors. Thanks to its such tightly wound data track, it can store 25 GB of data, which is over five times more than the DVD. The BD-ROM is not quite yet a full-on replacement for the DVD-ROM, though. The extra data capacity isn't free; BD-Rs cost considerably more than DVD-Rs. Not to mention that very few computers have Blu-Ray drives. In fact, many new computer models lack an optical drive altogether!

Is Optical Media Dead?

Optical discs have been heavily used in the multimedia and computer industries. First, CDs became commonplace in music distribution. As time passed, digital music became a worthy, more convenient alternative. DVDs came along next to revolutionize movie distribution. BDs then greatly improved movie quality. They, too, have a strong competitor, Internet video, again for having sharply increased convenience. Optical media are still here to stay for a little while longer in the multimedia field. Who knows, maybe it will turn around and start getting popular again. Having said that, chances are good that, in a decade or two, optical disc readers will become a rarity. A similar story goes for computers. Years ago, most software could only be installed via CD. For larger software that couldn't fit on a CD, the DVD could be used. Now the majority of software is downloaded through the Internet, without any physical discs. Recordable versions of all three types of optical media have also been used rather often. CDs showed many applications in their day, like to store photos from a studio or a presentation for work. DVDs, too, were great ways to share home movies and other media with friends and family. Again, their uses are gradually declining. For personal use, many prefer a modern USB flash drive or even a portable hard drive to less reliable, non-erasable, lower-capacity optical media. For long-term use, burned optical discs will degrade in readability over time. For any use, including sharing with others, Internet cloud-based storage is currently trumping most storage media. What is this leading to? The ultimate demise of optical media. Major computer manufacturers are already removing optical drives from many of their new models. This helps in making thinner, lighter computers while simultaneous saving the consumer several dozen dollars on something that an increasing number don't need. Of course, external disc drives are still widely available. Nonetheless, if optical media continues on its current path, it will be considered a legacy technology by most a couple of years from now. Personally, I'm not fully in support of this movement. I think that optical media still has some untapped potential through things like the M-Disc. Sadly, the majority doesn't agree with me. Do you think that the inevitable demise of optical media is coming soon, and are we ready for it?