Explain the Main Benefits of Canned Foods?

The main benefits of canned foods are:

(a) They are safe and hygienic and have logically good nutritional value;

(b) They are economical as the whole contents can be eaten, in which 30~50% of fresh food cannot be eaten because of perishing and loss in weight; and

(c) They come in a wide assortment, from major dishes to side dishes and desserts, and have utility value; and

(d) They maintain for a long period.