Pure milk and fresh milk have differences in shelf life, sterilization methods, packaging, nutritional value and so on. 1. Shelf life: the shelf life of pure milk is generally about half a year, at room temperature and light environment can be preserved, while fresh milk needs to be preserved in a low-temperature environment, the shelf life is generally only about a week. 2. Sterilization method: the sterilization method of pure milk is instantaneous autoclaving, while fresh milk is pasteurized. 3. Packaging: domestic pure milk is usually packaged in Tetra Pak, and fresh milk is usually packaged in bottles or bags. 4. Nutritional value: pure milk after autoclaving, may lose some nutrients, while fresh milk can maximize the preservation of milk nutrients. Milk is rich in protein, calcium and other nutrients, has a high nutritional value. Although it is rich in nutrients, it should not be consumed in excess. Drinking too much at one time may cause gastrointestinal and other digestive discomforts. People who are allergic to milk should not consume milk and its products.