H.264/MPEG-4 AVC is a standard for video compression. DivX® 7 is based on the H.264 standard, as well as Apple QuickTime 7. H.264 delivers the same quality as MPEG-2 at a third to half the data rate and up to four times the frame size of MPEG-4 Part 2 at the same data rate.
H.264 is most popular for its use on Blu-ray Disc, HD DVD and videos from the iTunes Store.