Plywood is a type of engineered wood made from thin layers, or "plies," of wood veneer that are glued together. The layers are arranged with their grain directions alternating, which enhances the strength and stability of the material. Plywood is commonly used in construction, furniture making, and various DIY projects due to its durability and versatility. There are different grades and types of plywood, including marine plywood, which is designed for use in wet conditions, and exterior plywood, which is treated to resist moisture. Plywood can be found in various thicknesses and sizes, making it suitable for a wide range of applications.