Which foam is best, hard or soft?

Which foam is best, hard or soft, depends entirely on application and personal preference, as each has advantages for different uses. Hard foam, also called rigid or closed cell foam, is best for insulation, structural support, packaging protection, and situations requiring durability, water resistance, and high R-value, such as rigid foam boards for house insulation, foam for flotation devices, and hard foam for construction. Hard foam provides firm support and does not compress easily. Soft foam, also called flexible or open cell foam, is best for comfort applications like mattresses, pillows, sofa cushions, and seating where cushioning, pressure relief, and conforming to body shape are desired. Soft foam like memory foam and high resilience foam provides comfort and is breathable. So hard foam is best for insulation and protection, soft foam is best for comfort and cushioning. Many products like mattresses use combination of hard base foam for support and soft top foam for comfort to get benefits of both.