Canning is really one step beyond cooking. It is a method that applies heat to food in a closed glass home canning jar to stop the natural spoilage that would otherwise take place, and removes air from the jar to create a seal. Canning provides a shelf life typically ranging from one to five years, although under specific circumstances it can be much longer.
A look at canning and why it is vitally important that every prepper have a basic understanding of how to preserve foods for long term storage. During SHTF food supply disruption will lead to seasonal abundances of food and your ability to preserve them and make use of them year long will be key to long term survival. Have the equipment to can is a great prep, and the knowledge is even better. it is relatively cheap to do, requires little equipment, and provides a huge amount of self reliance.