non-impact printers, the characters and images are form without any direct physical contact of the paper.
impact printers are noisily because of the hitting activity.
and non-impact printers are usually more expensive than impact printers.
In non-impact printers the text or image is formed without any physical contact of the paper and the printer head. But in impact printers the paper and the printer head come in contact and hence the text or image is formed.