Stone is the most abundant natural material that is available on earth. Stone has many uses.
Some of the earliest recorded finds have been tombstones. Being indestructible these tombstones have left a trail of history.
The information carved on such tombstones was hand carved. Stone masons used a stone chisel and patiently carved letters and later symbols.
Today this job has been taken over by a machine. This is the Stone CNC Router machine. CNC stands for computer numerical control.
All you need to do is transfer the design for a tombstone via CAM software into the computer of the CNC router machine.
The router will faithfully copy the design by engraving the stone with repeated passes to get depth.