How to keep food from rotting?

The cause of food spoilage is microorganisms that use substances from the food for their own life.
It can be concluded that providing unfavorable conditions for the growth of bacteria and fungi will save food from rotting.
1) Bacteria that cause food rotting aerobic organisms. Restricting oxygen access to foods leads to their death. Vacuum packaging is perfect for this.
2) When food is heat-treated during cooking, bacteria also die.
3) When warm, microbial growth increases, so both raw and cooked foods should be stored in the refrigerator or any other cool place.
4) Food preservation keeps water activity to a minimum. Water is a habitat for microorganisms, therefore conservation deprives them of this environment and the possibility of further development and spoilage of food. (Any other method of preparing products that reduces the amount of water in it is also suitable: salting, drying and drying)
5) When fermenting food, lactic acid bacteria release organic acids that prevent the development of mold.