Different materials have different properties. Some allow heat to move through them, whereas others prevent it. These materials have different names. Substances that allow heat to travel through them are called conductors; they are usually metals and are used in cooking to make use of their property.
Other items, which do not conduct the heat, are called insulators. They are used where humans need to protect themselves from heat such as in the walls of the buildings or the ceilings or the handles of cooking utensils. Knowing the different properties of different materials allows humans to exploit them and make life better for themselves.