When you scan an image, does it look more like a duplicate made by a photocopier? Does enlarging your image give you headache because you always get a sort of colored boxes, instead?
A scanner is just like a photocopier. The only difference is that, a copier creates a copy to a paper while a scanner transmits the scanned object into the computer, thus, creating a digital image of any printed material. The transferring of image to the paper is done by a printer.
One purpose of scanning is to allow you to edit images. You must have, of course, a printed material of what you want to scan. The scanner will create a copy of it on the computer. You can now edit it and print it afterwards. You must always remember that the quality of the duplicate will never be as good as the original. If you want to make a copy closer to original, the solution is on the correct adjustments of the scanner.
Scanning images, whether color or black and white, are always associated with the word resolution or dpi. For you to achieve the image quality you desire, you should know and understand how these affect your image.
Resolution refers to the number of pixels contained in the monitor. Pixel, from the words