Canning is a method of preserving food
Food preservation
Food preservation is the process of treating and handling food to stop or slow down spoilage and thus allow for longer storage....

 in which the food contents are processed and sealed in an airtight container. Canning provides a typical shelf life ranging from one to five years, although under specific circumstances a freeze-dried canned product, such as canned, dried lentils, can last as long as 30 years in an edible state. The process was first developed as a French military discovery by Nicolas Appert
Nicolas Appert
Nicolas Appert , was the French inventor of airtight food preservation. Appert, known as the "father of canning", was a confectioner.-Biography:...

 in 1810.