PU (Polyurethane) and PE (Polyethylene) foams serve critical purposes in cushioning, insulation, and protection, but differ in application: PU foam offers soness, flexibility, and excellent thermal/acoustic insulation (furniture, bedding, construction), while PE foam provides superior shock absorption, durability, and moisture resistance for heavyduty packaging, sports gear, and automotive parts, with PE oen being closed-cell and rigid for protection, versus PU's open-cell soness.