Lithograph Video

I am becoming more and more interested in printing methods and am currently reading 5 printmaking and drawing books and kept coming across the phrase lithograph. When I had asked our print tutor he told me it was done with stone but I couldn't fathom how this was done so I had to see it, and I came across this video.

It has ignited my imagination and I am knee deep in books and the moment and shall report back with some fantastic imagery soon...