Dear Mr. Kuttler.
TWAIN is a software interface between a graphics application and an image acquisition module (sotware that scans images from a scanner or reads images from a digital camera or from harddisk).
With the SilverFast
Ai TWAIN modules, you can scan images directly from your scanner into your application.
SilverFast
DC,
HDR and DCPro are special modules, which do not support scanners, but can read images from your harddisk.
Best regards.
Eric Flyvbjerg.