1) What is MP4? I have heard it is a "container format"? What's that? A container format allows you to combine different multimedia streams (most of the time audio and video) into one single file. Multimedia containers are for example the well known AVI (.avi), MPEG (.mpg, .mpeg), Matroska (.mkv, .mka), OGM (.ogm), Quicktime (.mov) or Realmedia (.rm, .rmvb) MP4 is the global file extension for the