 A variation of Hodge structure is a family of Hodge structures parameterized by a manifold, first studied by Phillip Griffiths (1968).All these concepts were further generalized to mixed Hodge modules over complex varieties by Morihiko Saito (1989).A pure Hodge structure of integer weight "n" consists of an abelian group formula_1 and a decomposition of its complexification "H" into a direct sum of complex subspaces "H""p","q", where "p" + "q" = "n", with the property that the complex conjugate of "H""p","q" is "H""q","p"