Tempered glass

Three to five times stronger than plane glass, when broken tempered glass develops hairline cracks or breaks into many small rounded pieces, much like auto windshields. It is recommended for use in areas where people might run or fall against them.

Insulating glass

Usually consists of two or three sheets of glass, held in a frame separated by a thin air space, much like the way a thermos is built, thus making it a good temperature insulator. Almost all living area windows are double or triple-paned. These type of glass are energy savers due to their high insulating capabilities (in some states you may even get a rebate from your Department of Water and Power).