The word
Pornography is
Greek, meaning "writing of
harlots", probably deriving originally from the signs hung outside ancient greek
brothels.
Pornography in general can be divided into erotica, which centers on "normal" heterosexual love, describing it in detail, and exotica, centering on so-called abnormal sex, including sadism, masochism, and fetishism.
Pornography is a very old interest of the human race, and examples of it can be found in elements of the Old Testament as well as in the plays of Aristophanes among other places, although its historical origin undoubtably goes back much further than that.
The first masterpiece of English pornography is most likely John Cleland's 1749 Memoirs of the Life of Fanny Hill.
See also: de Sade, Masoch, Twain, Reade, Porneius