A weed mat is a protective layer made from synthetic or natural materials that is laid over soil to prevent the growth of weeds. These mats are typically made from woven or non-woven fabrics, such as polypropylene or polyester, and they are designed to block sunlight, which is essential for the germination of weed seeds. At the same time, weed mats are porous, allowing water and air to pass through to the soil, ensuring that the plants' roots remain nourished.