Is a video format similar to MP4. The difference between the formats is their developers and protection. Apple company, has developed a format that has provided DRM-lock for M4V. Video files in this format are downloaded from iTunes.
SND is a file extension for a sound file used with a variety of platforms. SND stands for SouND. SND files may contain audio data specific to a Macintosh sound resource (from Mac OS Classic), an AKAI MPC audio sample, a generic Amiga sound, or other audio file. SND files can often be opened by Apple’s Quicktime Player