Agatha Christie is a renowned British author who wrote mystery novels and short stories. She is best known for her detective fiction featuring characters such as Hercule Poirot and Miss Marple. Christie's works have sold over two billion copies, making her the best-selling novelist of all time. Her books have been adapted into plays, films, and television series. Christie is often referred to as the 'Queen of Crime' and is considered one of the most important and innovative writers in the genre.