DVD, which stands for Digital Video Disc or Digital Versatile Disc, is the next generation of optical disc storage technology. It's essentially a bigger, faster CD that can hold video as well as audio and computer data. DVD aims to encompass home entertainment, computers, and business information with a single digital format, eventually replacing audio CD, videotape, laserdisc, CD-ROM, and perhaps even video game cartridges. DVD has widespread support from all major electronics companies, all major computer hardware companies, and about half of the major movie and music studios, which is unprecedented and says much for its chances of success.

We as a class are more interested in DVD as a storage medium than a movie medium, BUT there can be scientific uses as a "movie" medium for presentations and high quality video playback on DVD-Video (in two different  MPEG-2 formats).

The video playback of a movie in a DVD player depends on what format (of MPEG-2) it was recorded in. Currently the two video formats are NTSC & PAL. The max Rate for NTSC is 720x480 pixels @ 29.97 Frames/sec @ 60hz display. The Max rate for PAL is 720x576 @ 25 Frames/sec @ 50hz display. There are 540 lines  of resolution on a standard TV (4x3) display and 405 on a wide screen (16x9) compared to 230 you get while using VHS as a medium for video display (~500/375 respectively after filtering by player).

   VS. 

vs. 

1. About 8x more storage space in DVD than CD
2. DVD-ROM drives can read CD-ROM titles & CD-R but sometimes not CD-RW because dye used is not reflective enough for laser to pick up reflected signal.
 

SHORT ANSWER: MONEY & PATENTS....

    The DVD Forum's members spent over a year trying to agree on a single re-writable format. Unfortunately, while technological superiority and backwards compatibility were small factors in their design, political and economic considerations were far more important. Each of several companies wanted their own patented technology to be included in the specification for re-writable DVD, and each one wanted the others' technology to be excluded or minimized. Ultimately, the design for DVD-RAM included many technology patents owned by Toshiba, Hitachi, and Matsushita, some of which are currently used in PD (phase-change dual) and MO; and excluded much of the technology patents from Philips and Sony, some of which are currently used in CD-R and CD-RW. Sony, Philips and Hewlett-Packard, along with Yamaha and Ricoh, decided to use these patented technologies, and others to make a re-writable DVD technology. Meanwhile, Pioneer developed a re-writable version of their DVD-R technology called DVD-R/W, which was eventually accepted by the DVD Forum under the name DVD-RW.

While it may appear as if the best course would be to settle on one re-writable DVD technology for all markets and applications, there is considerable support for the view that a single universal standard for high-density removable optical storage is neither necessary or desirable. There are distinct differences between the proposed formats, and, in the end, these differences may make one of them more suitable to a given application than another.
 

1. Copying my home DVD videos- none, there is copy protection encoded not letting one do this.
2. Backing up hard drive/copying audio cd/cd-rom- one can use a DVD-RAM to do this
3. Create your own DVD discs- Creation of DVD logical/application level format (DVD-video, DVD-ROM) can be done w/ DVD-RAM drive
4. Compatibility w/ most other DVD drives but limited rewrite (1,000 times)- use DVD-RW
5. Local storage of files/removability w/o disk degradation (100,000 re-writes)- use DVD-RAM
6. Make a movie of my Nobel prize acceptance and showing (in high quality cinema, and high fidelity sound of me thanking mom... for all she's done!!!) footage of what I've done in the lab- Use a CD-R and make your own movie w/ following equipment...
 

If you're rich enough, put together a system with the following components

a video digitizer ($300-$10,000)
an MPEG-2 video encoder ($150-$35,000)
a Dolby Digital audio encoder ($800-$5,000)
a DVD-Video authoring application ($500-$70,000)
a DVD-R recorder ($5,400)
Then take the following steps:

1. Digitize the audio and video from your tapes (VHS, Hi8, DV)
2. Encode the video into MPEG-2 (make sure the display frame rate is set to 29.97 frames/sec.)
3. Encode the audio into Dolby Digital (or, if your video is short enough that you have room on the disc, format the audio as 48KHz PCM)
4. Bring the video and audio clips into the DVD-Video authoring program
5. Create a menu or two if you're ambitious, and link the menu buttons to your video clips
6. Create some chapter points if you're really ambitious (if your authoring program supports this)
7. Write your finished product out to a blank DVD-R ($40)