This Module introduces students to the causes and characteristics of trafficking in wildlife, forest and fisheries products, the demand and supply that fuel this trade, and the various activities that define it, ranging from poaching to consumption. The purpose of this Module is to outline the causes, characteristics, and criminology of wildlife, forest and fisheries crime (and to complement, and prepare students for, the Modules on international frameworks and criminal justice responses to these crimes. Module 1 provides a general understanding of the patterns and dimensions of this crime type, the difficulties of separating legal and illegal trade, and, through specific exercises and examples, teaches students about some of the animal species and countries most affected by the illegal trade.