Most printers today are non-impact. In the past it was the opposite.
Impact printers are printers that strike the letter against a ribbon against the paper. They can use carbon paper and print multiple copies using that when doing one print. Today many people have never seen or used carbon paper and their extent of hearing of it is CC in emails which is carbon copy. The most common impact printer was the dot matrix printer and you may occasionally still see one used. Impact printers were noisy. Some electric typewriters were also able to be used as printers and were impact printers.
Non-impact printers put the image on the paper without striking the paper. They are quiet printers. The quality of the print can vary. They are quieter than impact printers. Today the three most common non-impact printers are thermal, ink jet and laser. Thermal printers are often used to print receipts and use special paper that is heat sensitive and print by applying heat to the paper. Leaving the paper in the sun has print disappear as it all turns dark. Ink jet printers work by spraying ink at the paper in the shaper of the character. Their quality is better and many people use them The last one is a laser printer and it works with a laser putting image in a drum and picking up toner and putting it on the paper and then going thru hot rollers to melt the toner on the paper. Most ink in ink jet printers is water soluble so if gets wet the ink runs. Laser printed pages are permanently in the paper and will not be affected by water.