Although imperfect, cooking and canning are the most common applications of heat sterilization. Boiling water kills the vegetative stage of all common microbes. Roasting meat until it is well done typically completely sterilizes the surface. Since the surface is also the part of food most likely to be contaminated by microbes, roasting usually prevents food poisoning. Note that the common methods of cooking food do not sterilize food - they simply reduce the number of disease-causing micro-organisms to a level that is not dangerous for people with normal digestive and immune systems.
Boiling to sterilise jars and utensils
Whilst an imperfect method of sterilisation, for the purpose of home bottling and preserving, immersing the bottles and caps in boiling water should be sufficient.
Another method is to wash the jars and lids in hot soapy water, rinse and then heat in the oven (180° C - 350° F - Gas 4 - Moderate/Medium) for 5 minutes.
I would think it very likely that immersing a normal jar or bottle in boiling water is likely to cause it to break. I would only use jars specifically designed for this purpose such as Kilner jars. Perhaps someone could clarify this point? Chef