This document provides an overview of Agatha Christie's famous detective characters Hercule Poirot and Jane Marple. It describes their origins, physical appearances, methods of detection, and popularity as depicted in Christie's novels. Hercule Poirot was a Belgian detective introduced in 1920 who used his "little gray cells" to solve cases through logical reasoning. Jane Marple, based on Christie's grandmother, was an elderly resident of the village St. Mary Mead who drew on observations of village life to solve crimes. Both characters became internationally renowned for their problem-solving skills through multiple novels and other media.