TWAIN is a standard for scanning devices. It was first released in 1992 for the computers running on Windows and Macintosh operating systems. The release of TWAIN has made the process of image scanning hassle-free. Before TWAIN, users have to select a special application to receive the image from the scanner, then save the image to the disk. After that, they were able to open that image in the software of their choice to work with.