Distributive laws of Boolean algebra state that
(i) X(Y + Z) = XY + XZ
(ii) X + YZ = (X + Y)(X + Z)
1st law X(Y + Z) = XY + XZ holds good for all values of X, Y and Z in ordinary algebra whereas X + YZ = (X + Y)(X + Z) holds good only for two values (0, 1) of X, Y and Z.