| Term | Definition |
| zone of saturation | Area where the spaces in sediment and rock are completely filled with water |
| groundwater | water within the zone of saturation |
| water table | the upper limit of the zone of saturation |
| zone of aeration | the area above the water table |
| porosity | percentage of total volume of rock that has pore spaces |
| permeability | ability of a material to transmit fluid |
| aquitards | impermeable layers like clay that stop water |
| aquifers | rock layer that can transmit water freely |
| springs | natural flows of groundwater |
| hot springs | springs that have hot water |
| geysers | hot springs where water is ejected with great force |
| well | hole bored into the zone of saturation |
| drawdown | effect where the water table around the well is lowered |
| cone of depression | conical depression in the water table |
| artesian | any situation where water rises higher than was initially found |
| stalactites | icicle rocks on ceilings |
| stalagmites | icicle rocks on floors |
| karst topography | areas that have been shaped dramatically by groundwater |