AIFF from PCM is a tool to convert files containing stereo or mono linear PCM sound data into AIFF format.
You can often get a file containing linear PCM sound data as a result of demuxing (extracting) individual streams from a DVD disk.
To help visualize here is an example: You authored a DVD disk using iDVD a long time ago. The burned disk is still there but your original soundtrack is no more available. Although you can extract the sound data from the DVD using other tools, this extracted file won't play. The problem is, that it will be extracted as PCM, which contains raw sound data. To play it, to import it into iTunes or to use it in iDVD again, the file has to be converted into another format. The file type most recommended to be converted to would be AIFF, and AIFF from PCM is a tool that can be of great help for this job.
AIFF from PCM can handle files containing linear PCM sound data as follow:
• mono or stereo
• 8 kHz, 16 kHz, 32 kHz, 22.05 kHz, 44.