Foam material is a lightweight substance made of gas trapped in a solid or liquid, like plastics or rubber, known for cushioning, insulation, and shock absorption, primarily classified as open-cell (soft, breathable) or closed-cell (rigid, waterproof). Common types include polyurethane (PU), polystyrene (Styrofoam), memory foam, polyethylene (PE), and EVA, each with unique properties for applications from furniture and packaging to construction and automotive parts.