J = 2 = 1 + 1 = L + S so L and S are parallel with each other and having the same direction
J = 1 lies between J = 0 and J = 2 so the 2 term most be perpendicular with each other and one of the terms give a value to J
J = 0 = 1 – 1 = L – S so L and S are parallel with each other but have opposite direction