We prove the existence of a linear isometric correspondence between the Banach space of all symmetric orthogonal forms on a JB *algebra J and the Banach space of all purely Jordan generalized derivations from J into J * . We also establish the existence of a similar linear isometric correspondence between the Banach spaces of all antisymmetric orthogonal forms on J , and of all Lie Jordan derivations from J into J * .Making use of the weak amenability of every C * -algebra, U. Haagerup and N.J. Laustsen gave a simplified proof of Goldstein's theorem in [21]. In the third section of the just quoted paper, and more concretely, in the proof of [21, Proposition 3.5], the above mentioned authors pointed out that for every anti-symmetric form V on a C * -algebra A which is orthogonal on A sa , the mappingReciprocally, the weak amenability of A also implies that every derivation δ from A into A * is inner and hence of the form δ(a) = adj φ (a) = φa − aφ for a functional φ ∈ A * . In particular, the form V δ (a, b) = δ(a)(b) is antisymmetric and orthogonal.The above results are the starting point and motivation of the present note. In the setting of C * -algebras we shall complete the above picture showing that symmetric orthogonal forms on a C * -algebra A are in bijective correspondence with the purely Jordan generalized derivations from A into A * (see Section 2 for definitions). However, the main goal of this note is to explore the orthogonal forms on a JB * -algebra and the similarities and differences between the associative setting of C * -algebras and the wider class of JB * -algebras.In Section 2 we revisit the basic theory and results on Jordan modules and derivations from the associative derivations on C * -algebras to Jordan derivations on C * -algebras and JB * -algebras. The novelties presented in this section include a new study about generalized Jordan derivations from a JB * -algebra J into a Jordan Banach J -module in the line explored in [31], [1, §4], and [8, §3]. We recall that, given a Jordan Banach J -module X over a JB * -algebra, a generalized Jordan derivation from J into X is a linear mapping G : J → X for which there exists ξ ∈ X * * satisfyingfor every a, b in J . We show how the results on automatic continuity of Jordan derivations from a JB * -algebra J into itself or into its dual, established by S. Hejazian, A. Niknam [23] and B. Russo and the second author of this paper in [33], can be applied to prove that every generalized Jordan derivation from J into J or into J * is continuous (see Proposition 2.1).Section 3 contains the main results of the paper. In Proposition 3.8 we prove that for every generalized Jordan derivation G : J → J * , where J is a JB * -algebra, the form V G : J × J → C, V G (a, b) = G(a)(b) is orthogonal on the whole J . We introduce the two new subclasses of purely Jordan generalized derivations and Lie Jordan derivations. A generalized derivation G : J → J * is said to be a purely Jordan generalized derivation if G(a)(b) = G(b)(a), for every a, b ∈ J ; while a Li...