Porosity refers to the measure of empty spaces, or pores, within a material. It is an important property in various fields, including geology, engineering, and materials science. High porosity means a material can hold more fluid, while low porosity indicates a denser structure. In geology, porosity is crucial for understanding how water and oil move through rock formations. It affects the storage capacity of aquifers and the extraction of natural resources. Porosity can be influenced by factors such as grain size, shape, and the arrangement of particles within a material.