A sponge is a porous material that can absorb liquids. It is often made from natural materials like sponge from the ocean or synthetic materials like polyurethane. Sponges are commonly used for cleaning, bathing, and in various industrial applications due to their ability to soak up water and other fluids. The structure of a sponge consists of many tiny holes, which allow it to hold liquid. When pressure is applied, the liquid is released, making sponges effective for wiping surfaces or soaking up spills. They are also used in art and crafts, as well as in scientific applications for absorbing substances.