The iPod is a line of portable media players designed and marketed by Apple Inc. The first line was released on October 23, 2001, about 8-½ months before iTunes was released and its most recent redesigns were announced on September 12, 2012. There are four current versions of the iPod: the ultra-compact iPod Shuffle, the compact iPod Nano, the touchscreen iPod Touch, and the hard drive-based iPod Classic.
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 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.
Prior to 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 "Video" are standardized across all iOS-powered products. While the iPhone and iPad have essentially the same media-player capabilities as the iPod line, they are generally treated as separate products. In the last few years, iPhone and iPad sales have overtaken those of the iPod.