Concept:Food preservation:Food preservation is a method by which food is kept from spoilage after harvest or slaughter.Such practices date to prehistoric times.Among the oldest methods of preservation are drying, refrigeration, and fermentation.Explanation:Usually, when a farmer is scared that his items will get bad (since vegetables get bad easily)they try to sell them even at low prices to get some money out of it, if not they will bear a loss in business.Thus, In an urban setting, a vegetable vendor cannot retain the product for a long time and decides to sell it immediately at low prices. This is because of distress as items are perishable.Additional InformationCold Storage:Cold storage is a facility that primarily stores food items that are short-lived and highly likely to get spoilt under normal conditions.These may include fruits, vegetables, fish, meat, etc.These food items are stored under optimum temperature(primarily low) and humid environment as required for individual items.