Groundwater - Basics:

Types of pore space:

Permeability:

Big concept: The water table is the basic description of how groundwater interacts with rocks. If I pour water into a bucket of unconsolidated sand, the water won't spread evenly through the bucket. It will collect at the bottom. As a result, we will have two hydrologic zones in the bucket:

Aquicludes: Aquifers can be unconfined or confined by impermeable rock layers called aquicludes.

At equilibrium, recharge and discharge are balanced. When equilibrium is disrupted, the elevation of the water table changes.
Speed of groundwater: Why isn't the water table level in an unconfined aquifer? Because flow of groundwater is slow.

Additional information.

How groundwater effects the landscape. In regions rich in carbonate rocks, the effect can be profound: