Auto Glass made after about 1965 is tempered safety glass. It is product that is hard and it is engineered so that when it brakes it fragments into small square shaped pieces instead of long sharp shards you will get if you brake a kitchen glass or bottle.
Auto Glass is also layered with an outside and inside piece of glass that has a sheet of special plastic between the layers to improve its structure and also retain the glass when it brakes.
Small chips that are outside of your view can often be fixed with a special epoxy type material that is injected into the pit and then polished once hard. If the chip or crack is directly in front of the drivers view it may not be able to be repaired and still pass inspection. If you go for a repair method make sure they warranty that it will pass inspection.
When you can’t make a repair and you must replace the glass I have to suggest that you foot the bill and get a professional to do the work. Front and rear windows are heavy and on new cars with complex curves doing the work will require at least two people and some special tools. It also requires you to work accurately and quickly to apply the new glass before the adhesive sealer skins over.
Do it yourself kits are available starting at about $10 and include a single component material which is injected into the crack or bulls-eye and allowed to cure. Better kits will provide a suction cup that can be placed over the chip reducing runs and flow while the material hardens.
Clean the glass with an ammonia based cleaner and wipe clean with water to remove any dirt and grease.
Apply the suction cup to the windshield and fill the suction cup with material to fill the crack.
Look for any air bubbles which will cause an imperfection.
Allow the material to cure as directed on the package.
Remove the suction cup and clean the area and make flush with a sharp single edge razor blade.
Note this material is not as hard as glass and will most likely require sanding and buffing to restore the surface at a later time.Using even high grade sandpaper on the surrounding glass can damage it so it is important that you prepare the area with masking tape then use a 3,000 grade sandpaper or finer.
Repairing cracks even if performed by a professional is a temporary fix. Eventually you will need to replace your windshied as there is a higher chance that the crack will extend and grow.
If the chip is in the direct area of vision even a professional repair may not pass your next vehicle safety inspection. This will depend on the quality of work and the safety rules in your state. Some states will only allow front windshields to be repaired within a 4 inch boarder around its edge. For this reason you should ask for a warranty that includes passing inspection from any professional performing the work.