Rashba effect plays an important role in solids when there is an inversion symmetry breaking. However, it is rather poorly understood in spite of the fact that it was proposed decades ago. We show that it is not the Zeeman splitting but the electro-static interaction of asymmetric charge distribution produced by local OAM of high-Z materials and electric field. Consequently, OAM forms a chiral structure and such chiral OAM is shown to be measured by angle resolved photoelectron spectroscopy with circularly polarized light. The characteristic spin chiral structure of Rashba states is formed through the spin-orbit coupling and thus is a secondary effect to the chiral OAM. Results from first principles calculations on a single Bi layer under an external electric field verify predictions of the new model, including the direction of the spin texture which is predicted to be in opposite direction to the conventional Rashba picture. We extend our understanding to general spin-orbit coupling case and apply it to the well-known surface states of Cu and Au. Evolution of the angular momentum structures as a function of the spin-orbit coupling is discussed.