what is the difference between black,white and green tea?

all of the teas are healthy, green tea has loads of antioxidants and other properties that lower the incidence for everything from glaucoma to forms of cancer. black tea may boost immunity, reduce hypertension and even lower the risk of ovarian cancer by upto a half (same as green tea by the way). I know that white tea promotes weight loss and can help reduce wrinkles, but I don't know much more than that. All three are considered healthy.