Underlayment is a layer of material placed between the subfloor and the finished flooring. It serves several purposes, including providing cushioning, sound insulation, and moisture protection. Common materials used for underlayment include foam, cork, and felt, depending on the type of flooring being installed, such as laminate, vinyl, or hardwood. In addition to enhancing comfort and reducing noise, underlayment can help extend the life of the flooring by absorbing minor imperfections in the subfloor. Proper installation of underlayment is essential for achieving the best performance and durability of the finished floor, making it an important step in the flooring process.