  The Hilbert spaces are common. But the direct connection between them is
rare. The aim of this paper is to establish a direct relation among the three
Hilbert spaces Hardy, Bergman and Dirichlet without defining any of the Hilbert
space in weighted sense. In order to accomplish this goal, this paper develops
the Littlewood-Paley type Identities for Bergman and Dirichlet space. After
defining these identities, the vision of connecting all the three Hilbert
spaces via a direct connection is achieved.
