SND file format is used to store digital audio data. This file format is not compressed and being simple in structure can therefore be used as pure audio file for a single sound sample or for storing single computer command.

When this file is opened in hex viewer, it can be seen that the first four bytes of SND file format represent SND text when decoded in ASCII. SND file format is used by NeXT software application as well as Apple Inc. Macintosh Sound Manager software application of Apple uses this file format to run the commands given to it and data stored in SND file is the command itself.