If you wanna preserve fruits or vegetables for the winter, you will need jars. For example, if you are pickling beets, consider that you need 2 jars of 720 ml for 1 kg of vegetables. When you are making a fruit jam, since the fruit evaporates quite a bit when cooked, you need only 1 jar for 1 kg of fruit. This is just a guideline, so keep in mind that it is always good to have a few jars extra.
Personally, I sterilize the jars by first washing them in the dishwasher. Then arranging them on a tray (they must be open), and putting them together with lid in the oven at 100 ° C. After the oven is heated, I leave them for another 15 minutes and then turn the oven off.
When you are making a jam, you will put hot jam in hot jars, and that will be enough for pasteurization. But if you are making pickled vegetables or you are putting any other cold contents in jars, you will still need to pasteurize it afterwards.