iTunes is a software application created by Apple Inc. that serves as both a media player and a library for storing digital audio and video files. It is compatible with computers running the OS X and Microsoft Windows operating systems. The iTunes Store can also be accessed on Apple devices such as the iPod Touch, iPhone, and iPad. Users can use the iTunes Store to purchase and download a wide variety of digital content such as music, music videos, TV shows, audiobooks, podcasts, movies, and movie rentals in select countries. Ringtones are also available for purchase on the iPhone and iPod Touch models released from the fourth generation onwards. Additionally, users can download application software for their Apple devices from the App Store.