You’ve probably heard of Blu-ray technology by now.  It’s usually described as the DVD equivalent of HDTV.  It’s much more.  Understanding most explanations of it requires a PhD, but there’s a much easier explanation for the rest of us.

The Blu-ray Disc Association (BDA) is a group of 170 entertainment and technology companies (all the big guys – Disney, Fox, Sony, Samsung, Warner Brothers, Sun, HP, Dell, Apple, etc) who got together to develop Blu-ray technology.

The biggest difference between Blu-ray Disc technology and DVD technology is the laser that’s used.  If you’ve ever seen the laser that your DVD player, PlayStation 2, or CD-ROM drive uses, you’ll notice that it’s red.  Blu-ray Disc technology uses a blue laser to read and write to the discs.  That explains the name – Blu from blue, and ray from optical ray.

The difference between the blue and red lasers is more than just color.  The blue optical ray uses a much shorter wavelength.  If you weren’t a physics major, don’t worry.  You don’t need to know any wavelength formulas.  All you need to know is that the shorter wavelength allows the laser to focus on a much smaller area.

The best way to think of it is to compare the lasers to cheap, stick pens like Bic or Papermate.  Yes, pens!  Some pens have a medium point, and some pens have a fine point.  If you make a dot on a piece of paper with a medium point pen, it is bigger than a dot made with a fine point pen.  Think of the traditional (DVD, CD-ROM) red laser as a medium point pen.  When it reads your DVD, it reads a medium point pen sized space.  The new blue laser is the fine point pen.  When it reads a disc, it reads a fine point pen sized space.  Because the fine point pen laser reads smaller spaces, you can cram more data on the disc and the fine point pen can read it all.

Because there is so much more space available on these discs, there isn’t a need to compress the video and audio like there is on DVDs.  Think about pictures on your computer.  The big, detailed pictures are usually huge files.  When you compress the file to make it smaller to fit on a disc or to send in an email, you lose a lot of detail.  The same happens with DVD movies.  Blu-ray Disc movies give you more detail on both the audio and the video.

Because you can fit so much information on both the front AND back of the discs, the longer DVD movies where you have 2 and 3 discs may become a thing of the past!

Blu-ray Disc players are still quite expensive because they are so new.  They will likely come down soon.  After all, there was a time when VHS players were over $1000!  You can also watch Blu-ray Discs (called BDs, not BRDs) on PlayStation 3 systems.