Soy Milk, Rice Milk Etc Etc

What exactly is Soy Milk, Rice Milk? I looked it up on the internet and I see the way to make them but basically it says to mush them up and soak them in water, drain the “water” which is now “milk.”

How does the protein and vitimins transfer to the water? Or is this wrong way of thinking about it.

The transfer is simply that it is easier to dissolve a mushed item in water than a whole item. All you’ve done is thin out the original mateial (minus some of the fibrous material that doesn’t dissolve). So pretty much everything that was in the original is now in the solution.