Iron displaces copper from its aqueous solution but the reverse reaction is not possible. Why?

Iron is more reactive than copper and lies above copper in reactivity series. So, it can displace copper from copper sulphate. But copper can not displace iron from iron sulphate as it lies below iron in reactivity series.

As more reactive metal can displace less reactive metal from the compound of less reactive metal, so, Iron can displace copper fromcopper sulphate solution but copper cannot displace iron from iron sulphate.