This is a question I'm asked a lot. I've written a full explanation here, but for those of you who just want the short version, here you go! Lactose is a component of dairy. So a product that is a labeled lactose-free just means that that product does not contain lactose but could contain another component of dairy, like casein or whey. So, a product that is lactose-free isn't neccessarily dairy-free, but a product that is labeled dairy-free is definitely lactose-free. Make sense? If not, read more here!