What is iPod?
iPod is a brand of portable media players designed and marketed by Apple Inc and launched on October 23, 2001. As of 2008, the current product line-up includes the hard drive-based iPod classic, the touchscreen iPod touch, the video-capable iPod nano and the screenless iPod shuffle. Former products include the compact iPod mini and the spin-off iPod photo (since re-integrated into the main iPod classic line). iPod classic models store media on an internal hard drive, while all other models use flash memory to enable their smaller size (the discontinued mini used a Microdrive miniature hard drive). As with many other digital music players, iPods, excluding the iPod touch, can also serve as external data storage devices. Storage capacity varies by model.
The larger iPod and the iPod Mini use an extremely small hard disk for storage. The Shuffle uses a type of memory known as flash; unlike the memory found in computers, flash memory does not lose its contents when the power is turned off. As the prices and capacities of both hard disks and flash memory continue to fall, the storage capacity of all three models has increased over time.
Apple's iPod continued the company's tradition of creating technology that is easy to use. When connected to a personal computer (PC), Windows or Macintosh, the iPod communicates with a piece of Apple software called iTunes. The iPod and iTunes work together to synchronize the songs available on the iPod to those available on the PC. This happens automatically, without any intervention being required from the user. This ease of use was a primary reason for the iPod's domination of the portable MP3 player market.
In addition to playing MP3 audio files, the iPod plays AAC. AAC, or Advanced Audio Coding, was developed by Dolby Labs as part of the MPEG-4 audio/video standard. While technically advanced as a compression algorithm, AAC's principle difference from MP3 is its ability to support Digital Rights Management (DRM). DRM is a response to the type of song sharing first enabled by websites like Napster. By encoding legally purchased songs with digital signatures, it increases the difficulty of sharing them inappropriately.