mp4 problems - how to differentiate them?

[theChameleonXXX]

hello, i read... ok, i glanced at the IANA's RFC 3555 and found out that there are many types of mp4. audio, and several types of video.

my problem is, how do u tell them apart? is there a website that has this information?

for example, wat is the header for each of these different types of files, and wat is the difference between them?

thanks