The iPod is a combination portable digital media player and hard drive from Apple Computer. The original version was about the size of a deck of playing cards, with a monochrome screen and a 5 gigabyte capacity. iPods can be now be purchased with up to 60 GB of hard drive capacity and color screens capable of playing television shows, videos or movies uploaded from a PC.
An iPod can be connected to a computer with either a FireWire or USB port, with many of the latest versions depending upon USB 2.0. iPods have a reputation for being user-friendly. Users navigate with what Apple calls a "touch wheel," a centrally-placed circular disk designed for one-hand operation. Popular iPod features include a calendar, address book, to-do list, alarm clock with sleep timer, games and text reader. A large variety of peripherals exist for the iPod beyond its iconic white ear buds, including modules that allow songs to be broadcast on radio frequencies, docks for digital cameras, digital voice recorders and docking stations that are integrated with stereo systems, powered speakers or even automobile entertainment systems.
While the iPod was originally platform dependent, after July 2004 iPods (and Apple's iTunes software, included with each unit) worked on either Windows or Mac. iTunes makes it possible to load an entire CD onto an iPod in as little as ten seconds, organize thousands of songs into favorite playlists, purchase songs, albums, videos and movies from the online store and subscribe to podcasts.
The iPod supports most audio file formats including MP3, WAV, and AAC. As of October 2006, the iPod was the world's most popular portable digital media player, with more than 60 million units sold worldwide.