Insulation protects against both heat and cold but also to dampen sound or in the case of fireproofing Mineral Wool fill voids that insulate and are highly fire resistant.

Insulation comes in batts, rigid and loose called Blowing Wool essentially for attics.

Related to insulation is polyethylene air/vapor barrier as well as caulking and acoustic sealant along with the installation tools, Kenroc has them all.