MP4 files are a type of computer video file. It is a common video file format used by portable media players, including the Apple iPod and iPhone devices. If you have a video file you want to play on your portable media player, you will need to convert it from whatever format it is currently in to MP4. To do this, you cannot simply change the file extension–that will damage the file. Instead, you must use conversion software to convert the video file to the MP4 file. Writer Bio
