An impermeable material would have small pores, if any, that are likely unconnected. Small pores limit the movement of substances through the material, and unconnected pores minimize the pathways for substances to traverse.
it has small pores because water can't pass through it and they are unconnected because if they were they're would be large pores.
Water contained in pores of soil or rock is groundwater..
A rock containing well-connected pores is typically called a porous rock. These connected pores allow for the movement and storage of fluids such as water or oil within the rock. Examples of porous rocks include sandstone and limestone.
Then fluid can travel through the rock, and the rock is said to be "permeable".
the zone in rock layers where all the pores are filled with water
Water can get into fractures/joints/pores of rock, freeze, and then expand, weathering the rock.
the zone in rock layers where all the pores are filled with water
Mechanical weathering
Yes, it is possible for a rock to have high porosity, meaning it has a lot of open spaces or pores, but low permeability, indicating that the pores are not well connected or that the rock's structure hinders the flow of fluids. As a result, while the rock can hold a lot of fluid within its pores, the fluid may not be able to flow easily through it.
Aquifer
The water table.