iTunes U is a section of the iTunes Store where users can download free educational course content from many colleges and universities, non-profit educational institutions, and K-12 organizations.
The content, which includes course lectures, lab demos, sports items, and campus tours, comes as audio and video files. The downloads are free. Content from 300 colleges and universities worldwide is available.
The program also includes content from non-higher-ed institutions, such as the 92nd St. Y, Public Radio International, The Museum of Modern Art, and Smithsonian Folkways.
Some K-12 educational content is also available from various state departments of education and international education organizations.
iTunes U Compatibility Audio files downloaded from iTunes U are in the MP3 format, so they're compatible with any device that plays MP3s, not just iTunes or the iOS.