iPod is a brand of portable media players designed and marketed by Apple and launched on October 23, 2001. The line-up currently consists of the original style hard drive-based flagship iPod classic, the iPod touch, the mid-level video-capable iPod nano, and the entry-level screenless iPod shuffle. Former products include the compact iPod mini (replaced by the iPod nano) and the high-end spin-off iPod photo (re-integrated into the main iPod classic line). iPod classic models store media on an internal hard drive, while all other models, aside from the Microdrive-based mini, use flash memory to enable their smaller size. As with many other digital music players, iPods can also serve as external data storage devices.
Apple's iTunes software is used to transfer music to the devices. As a jukebox application, iTunes stores a music library on the user's computer and can play, burn, and rip music from a CD. It also transfers photos, videos, games, and calendars to those iPod models that support them. Apple focused its development on the iPod's unique user interface and its ease of use, rather than on technical capability. As of October 2007, the iPod had sold over 119 million units worldwide (stated in "The Beat Goes On" conference) making it the best-selling digital audio player series in history.
