Lithography (from Greek λίθος - lithos, "stone" + γράφω - graphο, "to write") is a method for printing using a stone (Lithographic Limestone) or a metal plate with a completely smooth surface. Lithography uses oil or fat and gum arabic to divide the smooth surface into hydrophobic regions which accept the ink, and hydrophilic regions which reject it and thus become the background. By contrast, in intaglio printing a plate is engraved, etched or stippled to make cavities to contain the printing ink, and in woodblock printing and letterpress ink is applied to the raised surfaces of letters or images.
Invented by Bavarian author Alois Senefelder in 1796, lithography can be used to print text or artwork onto paper or another suitable material. Most books, indeed all types of high-volume text, are now printed using offset lithography, the most common form of printing production. The word "lithography" also refers to photolithography, a microfabrication technique used to make integrated circuits and microelectromechanical systems, although those techniques have more in common with etching than with lithography.
In the world of arts, the word litho is often used for prints of different sorts (silkscreen, lino, ...). Therefore, not every work that is called litho is actualy a lithograph.