Evaporate means that vapors (vapor is a originally latin word for steam) have left (the e-/ ex- syllable means an outward movement in Latin) the milk.
So if you buy "evaporated milk" or "condensed milk" then it has been heated until it was steam. And then cooled down so that it's liquid again. "To condense" means the process of a vapor becoming liquid again.
That milk is dead. There is no living lactose bacteria supposed to be in it anymore. It has hardly any vitamins. Yet it doesn't necessarily have less calories than normal milk. I would not recommend it as a drink. It doesn't taste like milk either. Some people use it to put the white in coffee.
I think they dehydrate it so it has a longer shelf life. So pretty much you dont haave to refrigrate it till you open the can, and it can las tfor a long time. and i think its less healthier
its pretty much milk that has had some water evaporated out of it :)
Simply milk that has had some of the water evaporated from it.