To make almond milk, manufacturers grind toasted almonds and then blend them with water. Almond milk sometimes includes additional vitamins and minerals. It has lower levels of protein than milk from cattle, so protein is often an addition as well.
Some people like to make their own almond milk at home because they can add whatever they want to the mixture. Almond milk sometimes contains sweetener. Commercially produced varieties such as Silk are available in many different versions for convenience. It is a good alternative for those who are allergic to dairy or want a low-calorie yet nutritious milk substitute for cooking.