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 8½ months after iTunes (Macintosh version) was released. 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.
As a portable electronic device, developed and manufactured by Apple, Inc. The iPod allow users to upload and play their music using the device. Users are able to take their music (typically in the initial form of compact discs) and upload it to their personal computers using a program called iTunes. The music files are converted by the program so that they can be played on the device. iPods also include other features including calendars, games, alarm clocks, and software to display digital photos. iPods come in a number of colors and memory sizes.
The iPod line can play several audio file formats including MP3, AAC/M4A, Protected AAC, AIFF, WAV, Audible audiobook, and Apple Lossless. Fifth and sixth generation iPod Classics, as well as third generation iPod Nanos, can additionally play MPEG-4 (H.264/MPEG-4 AVC) and QuickTime video formats, with restrictions on video dimensions, encoding techniques and data-rates.
Originally, iPod software only worked with Mac OS; iPod software for Microsoft Windows was launched with the second generation model. Unlike most other media players, Apple does not support Microsoft’s WMA audio format-but a converter for WMA files without Digital Rights Management (DRM) is provided with the Windows version of iTunes.