Image scanner or optical scanner is a type of scanner that generates a digital representation of an image for data input to a computer.
Image scanner definition
An image scanner (often abbreviated to just scanner) is an electronic device which can read or scan graphics, text or handwritten document and translate it into an electronic format that the computer can understand.
Various types of image scanners are as follows:
Nowadays, scanners generally use a charge coupled device (CCD) or a contact image sensor (CIS) as the image sensor, whereas older drum scanners use a photo-multiplier tube as the image sensor.