Although imperfect, cooking and canning are the most common applications of heat sterilisation. Boiling water kills the vegetative stage of all common microbes. Roasting meat until it is well done typically completely sterilises 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 sterilise 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.
Sterilisation (or sterilisation) refers to any process that effectively kills or eliminates transmissible agents (such as fungi, bacteria, viruses, spore forms, etc.) from a surface, equipment, article of food or medication, or biological culture medium. Sterilisation does not, however, remove prions. Sterilisation can be achieved through the application of heat, chemicals, irradiation, high pressure or filtration.
The first application of sterilisation was thorough cooking to effect the partial heat sterilisation of foods and water (for drinking). Cultures that practice heat sterilisation of food and water have longer life expectancy and lower rates of disability. Canning of foods by heat sterilisation was an extension of the same principle. Ingestion of contaminated food and water remains a leading cause of illness and death in the developing world, particularly for children.
Food sterilisation is usually considered a harsher form of pasteurisation, and is carried out through heating, though other methods are available. Food sterilisation is commonly a part of canning and is used in combination with or instead of preservatives, refrigeration, and other ways to preserve food.
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