The iPod is a line of portable media players and multi-purpose pocket computers designed and marketed by Apple Inc. The first line was released on October 23, 2001, about 8 1/2 months after iTunes (Macintosh version) was released. iTunes is a media player, media library, and mobile device management application. The most recent iPod redesigns were announced on September 12, 2012. There are three current versions of the iPod: the ultra-compact iPod Shuffle, the compact iPod Nano and the touchscreen iPod Touch.

Like other digital music players, iPods can serve as external data storage devices. Storage capacity varies by model, ranging from 2 GB for the iPod Shuffle to 160 GB for the iPod Classic. The devices are controlled by the Samsung ARM and the Apple A5 CPUs.

Apple's iTunes software (and other alternative software) can be used to transfer music, photos, videos, games, contact information, e-mail settings, Web bookmarks, and calendars, to the devices supporting these features from computers using certain versions of Apple Macintosh and Microsoft Windows operating systems.

Before the release of iOS 5, the iPod branding was used for the media player included with the iPhone and iPad, a combination of the Music and Videos apps on the iPod Touch. As of iOS 5, separate apps named "Music" and "Videos" are standardized across all iOS-powered products. [3] While the iPhone and iPad have essentially the same media player capabilities as the iPod line, they are generally treated as separate products. During the middle of 2010, iPhone sales overtook those of the iPod.

 
     
  Wikipedia : http://en.wikipedia.org/wiki/IPod