Groundwater occurrence, movement and interaction with its geologic framework is treated following four fundamental aspects: groundwater as a natural system, a resource, an environmental system, and a managed system. As a natural system it is an integral part of the hydrologic cycle which determines its distribution, movement and interaction with the geologic, hydrogeologic and hydrogeochemical framework. The surface water/groundwater interface is emphasized. As a resource, its exploration, development, production and the available tools for mapping and simulation are presented. As an environmental system: aquifers act as dispersive propagation systems for chemical or pollution stresses, from which the groundwater resource and the environment have to be protected. Groundwater as a managed system deals with an integrated approach to its use, conservation, remediation, and quality control in the context of a larger holistic water resources picture. The objective of the course is to give a complete, quantitative overview to hydrogeology. The course will involve the use of field observations, lab and chemical data, as well as modeling as basic tools to understand and manage the groundwater resource.