Here's a breakdown of the key terms:

* Underground soil formation: Aquifers are geological formations, often made of rock, sand, or gravel.

* Sufficient saturated permeable material: This means the rock or soil must be able to hold water (saturated) and allow water to flow through it (permeable).

* Yields significant quantities of water: This means the aquifer can produce enough water to be useful for things like drinking water, irrigation, or industrial use.

Let me know if you'd like more details on aquifers, different types, or how they are used!