A compact disk is the long form of a CD. It's that circular thing with a silvery backside that contains all the music/movies/data/shit/porn that you downloaded from the net is usually stored. It is what you call the principle portable data storage method for the late twentieth century. A CD comes in two sizes, the larger CD has a capacity of 700 MB, or 80 minutes of sound, and the smaller ones have a capacity of 185 MB, or 21 minutes of sound. There are three kinds of CDs. PRe-recorded CDs that comes with software / music / data already burnt in. CD-Rs where you get to burn data, and CD-RW where you get to burn as well aas erase data. As of now, portable data storage is changing over to flash drives and DVDs.

Sony's newest system.

The PlayStation 3, will use Blu-Ray discs as its media format. The discs can hold up to six times as much data as current-generation DVDs. It will also support CR-ROM, CD-RW, DVD, DVD-ROM, DVD-R, DVD+R formats. It also confirmed the machine would be backward-compatible all the way to the original PlayStation. It will also have slots for Memory Stick Duo, a SD slot, and a compact flash memory slot. It will also sport a slot for a detachable 2.5 inch HDD somewhat similar the Xbox 360's.

Out of the box, the PS3 will have the capability to support seven Bluetooth controllers. It will also have six USB slots for peripherals--four up front and two in the back.

Sony also laid out the technical specs of the device. The PlayStation 3 will feature the much-vaunted Cell processor, which will run at 3.2 Ghz, giving the whole system 2.18 teraflops of overall performance. It will sport 256mb XDR main RAM at 3.2 Ghz, and have 256MB of GDDR VRAM at 700mhz.

Sony also unveiled the PS3's graphics chip, the RSX "Reality Synthesizer based on Nvidia technology. The GPU will be capable of 128bit pixel precision, 1080p resolution, some of the highest HD resolution around. The RSX also has 512mb of graphics render memory and is capable of 100 billion shader operations and 51 billion dot products per second. It also has over 300 million transistors, larger than any processor available commercially today. It will be manufactured using the 90nm process with 8 layers ...

KVCD is a modification to the standard MPEG-1 and MPEG-2 GOP structure and Quantization Matrix. It enables you to create over 120 minutes of near DVD quality video, depending on your material, on a single 80 minute CD-R/CD-RW. They have published these specifications as KVCDx3, their official resolution, which produce 528x480 (NTSC) and 528x576 (PAL) MPEG-1 variable bit rate video, from 64Kbps to 3,000Kbps. Using a resolution of 352x240 (NTSC) or 352x288 (PAL), it's possible to encode video up to ~360 minutes of near VCD quality on a single 80 minute CD-R. The mpeg files created will play back in most modern standalone DVD players. You must burn the KVCD MPEG files as non-standard VCD or non-standard SVCD (depends on your player) with Nero or VCDEasy.

Rotational velocidensity affects all audio files encoded with lossy compression. These include mp3, aac, and ogg.

The most notable effect of rotational velocidensity is the loss of bitrate in files. A lossy audio file will lose an average of 12kbps a year. But, this can vary greatly depending on the type of storage media used.

Examples:

SATA HDD: ~12kbps
IDE HDD: ~15kbps
SCSI HDD: ~7kbps
DVD: ~16kbps
CD-R/RW: >21kbps

This can be overcome by compressing audio using lossless formats such as FLAC, APE, or TTA. These formats are designed to never lose quality over time, and will sound the same right now as they will in 10 years.