Is h264 an mp4 ?

.mov is a container, like a cardboard box that has "films" labeled on the side.

You don't know from the label exactly what is inside the box (super 8mm? 35mm? VHS tape?) but you have an idea of what you'll find.

MtD

h264 is a codec. Video encoded with h264 codec can be wrapped as .mov or .mp4. Basically .mov and .mp4 are wrappers which can contain video encoded with different codecs.

Yes, it is confusing. Remember that a file extension is to tell the computer what application to use to open the file - which on a Mac is often handled by QuickTime. So when once the file is directed to QuickTime, then hopefully Quicktime has the correct components to playback the file - and it usually does. When it does not, some files, even if labeled .mov, won't playback on a Mac.

MtD

Yes it can be confusing because MPEG4(mp4) is also an encoder i.e. there is an mp4 encoder as well as .mp4 container. Perhaps this link will help http://stackoverflow.com/questions/10477430/what-is-the-difference-between-h-264 -video-and-mpeg-4-video