ADF (Automatic Document Feeder) is commonly used in copiers and scanners to feed multiple pages into the machine instead of scanning the pages one at a time.
Duplex refers to how many sides of a page the scanner is capable of scanning. For duplex, that number is two. It scans both sides of a page
Simplex refers to how many sides of a page the scanner is capable of scanning. For simplex, that number is one.
This refers to the resulting color of a scan, which will be in full color.
Color dropout is when the background image color is turned to white, while the text colors are converted to black. This is commonly used for OCR applications.
This refers to the resulting color of a scan, which will be in shades of gray and white.
This refers to the resulting color of a scan, which will either be black or white.
DPI (Dots per inch) refers to how many dots per inch are scanned on the image. 300 DPI means that the machine will scan 300 dots of information per inch. Resolution
The resolution of a scanner refers to amount of pixels the scanned image has.
LED (Light-Emitting Diode) is a semiconductor device that emits a light whenever an electric current passes through it. In scanners, this is the most power efficient and consistent light source. This results in better uniformity in the resulting scanned image.
A CIS (Contact Image Sensor) is a sensor that nearly allows direct contact with the object (e.g. piece of paper) and uses multiple LEDs (red, green & blue LEDs) to bounce light off of the object being scanned. It then captures the color that is reflected off the object and transcodes it into an image.