Porous media are materials that contain interconnected spaces or pores, allowing fluids like water or air to flow through them. Common examples include soil, rock, and certain types of concrete. The size and distribution of these pores affect how easily fluids can move, making porous media important in fields like hydrology and geotechnical engineering. In addition to natural materials, porous media can also be engineered for specific applications, such as in filtration systems or catalytic converters. Understanding the properties of porous media is crucial for managing resources like groundwater and designing effective environmental solutions.