The Hydrological Cycle. Rock Properties Affecting Groundwater. Vertical Distribution of Groundwater. Geological Formations as Aquifers. Types of Aquifers. Recharge. Groundwater Movement. Intrinsic Permeability, Hydraulic Conductivity, Storage Coefficient. Groundwater Levels Fluctuations and Environmental Influences. Saline Water Intrusion in Aquifers. Springs. Exploitation of Groundwater. Wells. Groundwater and Engineering Constructions. Pollution of Groundwater and Protection Methods.