From Mac GuidesiTunes is Apple's media player used for music, audiobooks, podcasts, and recently added music videos, television shows, and movies. Built on the QuickTime foundation, iTunes is compatible with all QuickTime encoded media.
As of October 2005, iTunes has captured more than 80% market share of digital audio players in markets supported on both the Mac OS and Windows platforms.
The iTunes Store (originally the iTunes Music Store) was launched and integrated into version 4.0 of iTunes in April of 2003, enabling customers both on Mac and Windows platforms to purchase audio files, encrypted with Apple's Fairplay technology, over the internet for individual use. The release of the iTunes Music Store delivered a more reasonable solution to obtaining digital audio files legally over the internet.
- Support for multiple media formats
- User-defined categorizing of content
- Built in Audio Encoder
- Built in visualizer based on Quartz Extreme
- Streaming internet radio
- Built in Podcasting Support
- Burn to multiple disc types: MP3, WAV Audio, and DVD
- Support for third party plugins
- Synchronize with Apple iPod portable media player, and the ROKR mobile phone from Motorola/Cingular Wireless
- Integrated iTunes Store, some songs are DRM Free and called iTunes Plus, other songs have DRM and don't have that label. DRM Free songs still have user information encoded on them.
- Ripping of users CD's into AAC, Apple Lossless, MP3, AIFF or WAV formats. Songs don't have user information encoded on them.
- Playlists and Smart Playlists
- Album Cover Artwork
iTunes 7.0 was released at a special event on September 12, 2006. This coincided with the renaming of the iTunes Music Store to the iTunes Store, and the beginning of movie and iPod game sales through the store.
- New interface
- Allows purchase of Movies
- Gapless playback
- iPod management in main window
- Re-Organized "Source" list
- Album Art download
- Download manager
- Multiple views: standard, Album Art, Cover Flow
A number of minor updates were made to iTunes 7, adding support for the Apple TV, iPhone, Windows Vista and iTunes Plus (DRM-free songs), adding several minor features and fixing a number of bugs. The current version, released on January 15, 2008, is iTunes 7.6. 
Supported Media Formats
- Video: Quicktime compatible video
- Audio: MP3, WAV, AIFF, MPEG4, Apple Lossless, M4P/AAC Protected Content, and a variety of quicktime supported media formats as well.
- The Windows version of iTunes supports converting unprotected WMA's to AAC or MP3.
- It is not possible to browse the library by composer.
- While it is possible to listen to one CD while importing another (if you have more than one drive), it is not possible to import more than one CD at a time.
- The Podcast Chapter jumping tool is now available only in the menubar
For information on previous versions see iTunes Version History.