What is the padding in walls called?

The padding in walls is commonly referred to as insulation. Insulation is used to reduce heat transfer, enhance energy efficiency, and improve acoustic performance in buildings. There are various types of insulation, including fiberglass, foam, cellulose, and mineral wool. In some cases, particularly in sports facilities or areas where impact protection is needed, wall padding can also refer to impact-resistant padding or safety padding used to protect people from injury.