Hardwood flooring is made entirely of a solid wood species like oak, maple, or walnut. Engineered wood floors have a thin top layer of hardwood bonded over plywood, making them less expensive. Engineered wood floors may be refinished 1 to 5 times, while solid hardwood floors may be refinished 4 to 10 times. Other than refinishing, both types of flooring have similar benefits and drawbacks.