Select the appropriate type according to the contents of the original in order to scan it with optimal level of image quality.
For details, refer to Here.
Adjust the density (Dark or Light) to scan the original.
For details, refer to Here.
You can adjust the density of the background area for originals with colored backgrounds (newspaper, recycled paper, etc.) or originals that are so thin that text or images on the back would be scanned.
For details, refer to Here.