The book "Groundwater" offers a comprehensive analysis of the challenges and techniques in the field of groundwater management. Given the increasing demand for water resources, particularly in developing countries, it is crucial to manage the limited groundwater resources efficiently. This technical book addresses the need to locate highly productive wells in hard rock regions using geophysical methods. It highlights the application of electrical imaging techniques in conjunction with remote sensing and geographic information systems (GIS) as promising tools for optimizing groundwater management. Additionally, it discusses the hydrodynamics of fractured aquifer systems, which are not yet fully understood, as well as the migration of groundwater contaminants and the intrusion of saltwater into coastal aquifers. The book aims to provide a better understanding of groundwater modeling and the associated challenges.