What is "waterjet" cutting?

A "waterjet" cutting system utilizes a narrow stream of water under extremely high pressure to "erode" a precise and narrow path through material to be cut. A cutting table located over a capture/recycling tank holds the workpiece in place while a cutting nozzle directs a water stream which impacts material at speeds faster than the speed of sound. The entire cutting assembly travels along a CNC (Computer Numerical Controlled) track which is controlled by various CAD (Computer Aided Design) software. Nonmetals and relatively soft materials can be cut using pure water. For harder materials such as metals and stone, a garnet abrasive is added to the water to augment it's cutting ability.