Butter is a very concentrated form of milk. The butterfat clumps together and separates from the water - which is known as buttermilk. The buttermilk can also be used to make evaporated milk. The butter is then kneaded to remove more buttermilk. The traditional method of churning butter takes about 40-60 minutes.
Modern methods can produce butter in seconds.
Ice cream is a mixture of milk, sugar, cream, flavoring and stabilizer. The stabilizer is used to prevent ice crystals from forming in the ice cream. The mix is then quickly cooled to 40 o F. Cultured milk products are another type of dairy product. These include items such as buttermilk, sour cream, and yogurt. Now, lowfat or skim milk is used.