Your vehicles auto glass is much different than the laminate glass that you find on your windshield.  The glass on your vehicle (other than your windshield) is all tempered glass.  Tempered glass is significantly more durable than standard glass, which is why it's used in your car in case of any sort of accident or unanticipated collision.  Tempered glass is created by heating and cooling the glass to create a hardened piece of glass.  Tempered glass is also designed to shatter into very tiny pieces of glass in the event it is every broken rather than created large shards of glass like normal glass does.  This prevents more injury or damage in the even of a car accident.

Tempered glass is different than the laminate glass that your windshield and your back car window are made of.  Windshields & back windows are made with laminate glass which is basically several pieces of glass pressed together at high temperatures and bonded together with glass resin to create one single sheet of glass with multiple layers.  Laminate glass is not quite as strong as tempered glass, but it does not shatter as easily.  Laminate glass is designed to bend and flex and should never shatter.

Minor chips and cracks in tempered auto glass can be repaired, but because of the glass is prone to shattering, we recommend a qualified auto glass technician give you a professional opinion regarding whether it needs to be repaired or replaced.