Landscape fabric is constructed from woven fibers or manufactured as a solid sheet with perforated holes to allow water to soak through. Some brands offer UV protection to maintain the life of the fabric.
No, landscaping fabric is not waterproof. While a major feature of landscaping fabric is that it holds moisture in the soil, it is still permeable. Water needs to be able to enter the soil, or else your plants’ roots will dry out and die. How Permeable Is Landscaping Fabric?