Cover Flow is an animated, three dimensional graphical user interface.
Cover Flow is an animated, three dimensional graphical user interface integrated within iTunes, the Macintosh Finder, and other Apple Inc. products for visually flipping through snapshots of documents, website bookmarks, album artwork, or photographs.
Only available internally to Apple applications via private frameworks, developers have a number of third party and open source options available to achieve the same effect, such as OpenFlow, iCarousel, flowcover, among others.