What is Impact Printing? What types of Impact printers are there? Why do they still exist?

Question

anonymous · Answer

The name is actually very accurate, it is when the transfer of ink to paper is accomplished via some form of pressure applied usually to a ribbon between the paper and the printing mechanism

anonymous · Answer

Just adding to seandisanti's answer (which is totally correct), a type of impact printer is the ol' dot-matrix which was very common years ago. 

There are a few reasons why they still exist, but the biggest ones are that they're relatively cheap (ink ribbons are incredibly cheap compared to buying ink wells for inkjets) and pretty rugged pieces of equipment that aren't as sensitive to dirt and grit. It's one of the reasons you might find one on a factory floor as opposed to a fancy color laserjet.