Between steel,glass fibre,wood,air,copper ,which material lies between two panes of glass in double glazed windows and why?

Air is typically used as the material between two panes of glass in double glazed windows. This is because air is a good insulator, helping to reduce heat transfer between the inside and outside of a building. Additionally, using air as the insulating material is cost-effective and environmentally friendly compared to other options such as argon gas.

Air lies between two panes of glass in double glazed windows.

This is because air is a poor conductor of heat, so it helps to keep the heat in during the winter and the heat out during the summer. Glass is a good conductor of heat, so if there were no air between the panes of glass, the heat would be able to escape through the glass easily.