We show that having a Wolf degree of coherence of unit modulus or having intrinsic degrees of coherence of unit modulus imply different relations between the electric fields of the light. Such relations are discussed in the mean square meaning. On one hand, we demonstrate, that if the intrinsic degrees of coherence are equal to one, then there is a linear relation between the electrical fields. On the other hand, we show that a Wolf degree of coherence of unit modulus corresponds to a stronger property that implies that the fields have to be proportional.