That means that water on the surface will try to seep into the ground below it. The rock below the Earth's surface is the bedrock . If all bedrock consisted of a dense material like solid granite, then even gravity would have a hard time pulling water downward. But Earth's bedrock consists of many types of rock, such as sandstone, granite, and limestone. Bedrocks have varying amounts of void spaces in them where ground water accumulates.
Bedrock can also become broken and fractured, creating spaces that can fill with water.
In many places, if you looked at a vertical cross-section of the earth you would see that rock is laid down in layers, especially in areas of sedimentary rocks . Sometimes when building a road, the layers are revealed by road cuts, and water can be seen seeping out through the exposed layers. Try as it might, gravity doesn't pull water all the way to the center of the Earth. Deep in the bedrock there are rock layers made of dense material, such as granite, or material that water has a hard time penetrating, such as clay. These layers may be underneath the porous rock layers and, thus, act as a confining layer to retard the vertical movement of water.