When combined with your computer and printer, the scanner can masquerade as a copy machine for light duty copying. The included software simply scans in the image you want to copy and then immediately sends the image to your printer. This works very well for occasional copies, but is no substitute for a heavy-duty office type copier. Simply scan in the document and print it out via your fax modem and software. As the models go up in price they get faster and the image quality gets better.
Most basic models work pretty well for the applications described above.
However, if your main concern is high quality graphics, be prepared to spend a bit more. Another thing to look for is how the scanner connects to the computer. A very common method on inexpensive models is to use the computers printer port. The scanner connects to the back of the computer and the printer connects to the back of the scanner, so you can continue to use your printer. Even better is the Universal Serial Bus connection.