Communicable infectious diseases are caused by microorganisms, called pathogens (viruses, fungi, bacteria, parasites) that infect a living organism, called the host. This chapter summarizes the evolution of knowledge on the contagiousness of diseases and their modes of transmission in an epidemic context, emphasizing the link between daily mobility and epidemiology. It addresses the modeling of daily mobility and discusses different modeling methods and the concepts used in an epidemic context. Special emphasis is placed on the most recent classes of models, namely individual-based models. These models integrate geographic information as well as social and epidemiological knowledge into a single formalism, enabling exploration of a wide variety of scenarios. Finally, the chapter prompts a selective literature review, dedicated to the data currently in use to better understand daily mobility and to calibrate increasingly detailed epidemiological models.