There are two main types of insulation:
Bulk insulation which acts as a barrier to heat flow between your house and the outside, keeping heat out in the summer and in your home in the winter. It comes in rolls, boards and batts and can be made of glass wool, polyester, natural wool or recycled paper.
Reflective insulation is usually used in houses in hot climates and deflects radiant heat. It's usually shiny aluminium foil laminated onto paper or plastic.
Some insulation products are available that combine the features of bulk and reflective insulation.
The type of insulation that is best for your home depends on whether you need to keep heat in or out or both. The design of your house, the materials it is made from and the orientation are also factors to consider.