calli-yang is right. 豆浆,also 豆汁 in many areas( but 豆汁may refer to another drink in the north), is the mixture of bean powder and water, used as a drink after boiled (mostly at breakfast); translated as 'bean milk' in many dictionaries, which literally means 豆奶。豆浆has hundreds of years long been popular drink among Chinese people.
豆奶 is a new type of drink, translated as the same 'bean milk' in some publication. It is a mixture of milk powder and bean power and used as nurishment and it is ready-to-eat that you put it into hot water and then Jhon is your uncle;)