Lithography..What does it mean?

Lithography (from Greek λίθος - lithos, "stone" + γράφω - graphο, "to write") is a method for printing using a plate or stone 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. Invented by Bavarian author Alois Senefelder in 1796,[1][2] it 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.

http://en.wikipedia.org/wiki/Lithograph

Litho printing is also known as lithography or lithographic printing or planography or planographic printing. Litho printing works on the basic principle that oil and water do not mix. Unlike relief printing and intaglio where the image and non-image areas are at different levels, in lithography there is only one surface.
In lithography a flat stone is treated in a manner so that the image areas attract the oil-based inks and the non-image wet areas repel the oil-based inks. When the stone is pressed against the surface to be printed on, the oily inked image areas leave an imprint of the desired design.

http://www.whatislithoprinting.com/

what is a lithograph?
Basically, it is a print made by using a press to transfer an image that was created initially on stone or metal plate to paper.
Aloys Senefelder, who invented lithography in 1798, preferred to call it "chemical printing", since the process depends on the chemical interaction of grease, nitric acid, gum arabic, and water, rather than the stone from which the name lithography is derived.

http://www.unm.edu/~tamarind/process.html

li⋅thog⋅ra⋅phy   [li-thog-ruh-fee] Show IPA Pronunciation
–noun
1. the art or process of producing a picture, writing, or the like, on a flat, specially prepared stone, with some greasy or oily substance, and of taking ink impressions from this as in ordinary printing.
2. a similar process in which a substance other than stone, as aluminum or zinc, is used. Compare offset (def. 6).
noun
1. a method of planographic printing from a metal or stone surface
2. the act of making a lithographic print

http://dictionary.reference.com/browse/lithography