Web Developers Recognize the Difference Between a Codec and a Platform
Video played using the H.264 codec must be played back in a "wrapper" application, or a web browser. The Flash player, like HTML5, also supports the H.264 codec as long as it also has the proper wrapper. The Flash video platform includes a whole system that features a player, server and DRM (content protection) technology.
Many readers are under the impression that any browser that supports HTML5 is going to work for all viewers, with all videos. The fact is that many of the browser companies themselves do not agree upon a video codec standard, and it may be several years before there will be a uniform video codec standard--if ever.