Lithography (from Greek λίθος, lithos, "stone" and γράφειν, graphein, "to write") is a method of printing originally based on the immiscibility of oil and water.
Printing is from a stone (lithographic limestone) or a metal plate with a smooth surface. It was invented in 1796 by German author and actor Alois Senefelder as a cheap method of publishing theatrical works.
Lithography can be used to print text or artwork onto paper or other suitable material.

Stone lithographic plates from the Deutsches Museum, Munich. image: R.Conan-Davies
Origins and process
Lithography originally used an image drawn with oil, fat, or wax onto the surface of a smooth, level lithographic limestone plate.
The stone was treated with a mixture of acid and gum arabic, etching the portions of the stone which were not protected by the grease-based image. When the stone was subsequently moistened, these etched areas retained water; an oil-based ink could then be applied and would be repelled by the water, sticking only to the original drawing.
The ink would finally be transferred to a blank paper sheet, producing a printed page. This traditional technique is still used in some fine art printmaking applications.
Source: Lithography. (2015, January 27). In Wikipedia, The Free Encyclopedia. Retrieved 04:50, February 7, 2015, from http://en.wikipedia.org/w/index.php?title=Lithography&oldid=644356152