In contemporary usage, a parody (or lampoon) is a work that imitates another work in order to ridicule, ironically comment on, or poke some affectionate fun at the work itself, the subject of the work, the author or fictional voice of the parody, or another subject. As literary theorist Linda Hutcheon (2000: 7) puts it, "parody...is imitation with a critical difference, not always at the expense of the parodied text." Another critic, Simon Dentith (2000: 9), defines parody as "any cultural practice which provides a relatively polemical allusive imitation of another cultural production or practice."

Parody exists in all art media, including literature, music, and cinema. Cultural movements can also be parodied. Light, playful parodies are sometimes colloquially referred to as spoofs. The act of such a parody is often called lampooning.

Source: http://en.wikipedia.org/wiki/Parody