Porosity refers to the degree or extent to which a material is porous, which means it contains small open spaces or voids within its structure. Porosity can be measured as a percentage and is often used to describe the properties of materials such as soil, rock, concrete, and metal. In general terms, higher porosity indicates that more space exists within the material for air, water, or other substances to flow through it. The specific characteristics of a porous material can have important implications in various fields, including engineering, geology, biology, and chemistry.