Discworld is a comic fantasy book series written by the English writer Terry Pratchett, set on the fictional Discworld, a flat disc balanced on the backs of four elephants which, in turn, stand on the back of a giant turtle, Great A'Tuin. The books frequently parody, or take inspiration from, J. R. R. Tolkien, Robert E. Howard, H. P. Lovecraft and William Shakespeare, as well as mythology, folklore and fairy tales, often using them for satirical parallels with current cultural, political and scientific issues. The series is popular, with more than 80 million books sold in 37 languages.
The Discworld novels contain common themes and motifs that run through the series. Fantasy clichés are parodied in many of the novels, as are various sub-genres of fantasy, such as fairy tales (notably Witches Abroad), witch and vampire stories (Carpe Jugulum) and so on. Analogies of real-world issues, such as religion (Small Gods), business and politics (Making Money), are recurring themes, as are music genres such as opera (Maskerade) or rock music (Soul Music). Parodies of non-Discworld fiction also occur frequently, including Shakespeare, Beatrix Potter and several movies. Major historical events, especially battles, are sometimes used as the basis for both trivial and key events in Discworld stories (Jingo, Pyramids), as are trends in science, technology, and pop culture (Moving Pictures, Men at Arms). There are also humanist themes in many of the Discworld novels, and a focus on critical thinking skills in the Witches and Tiffany Aching series.
Source: Wikipedia, "Discworld", available under the CC-BY-SA License.