Why does maltose have both alpha and beta anomers?

Maltose is a disaccharide that made of 2 glucose units. Each glucose unit can happen as alpha or beta. So, "α" or "β" is grounded on the relation between the stereochemistry of the anomeric carbon and the furthest chiral center in the ring. The α anomer is the one in which these two locations have the same configuration; they are opposite in the β anomer.