Closed-cell foam is a type of material made up of tiny, sealed bubbles that do not allow air or moisture to pass through. This structure makes it highly resistant to water and provides excellent insulation properties. It is commonly used in applications like insulation, buoyancy aids, and packaging. Due to its durability and rigidity, closed-cell foam is often used in products that require strength and support, such as protective gear and construction materials. Its ability to resist compression and maintain shape makes it ideal for various industrial and consumer applications.