A review is given of the present state of experimental and theoretical knowledge of the proton-proton and antiproton-proton forward scattering, with special attention to applications of phenomenological dispersion theory in elucidating this interaction. The topics covered include the treatment of unphysical region, low-energy parametrizations, dispersion relation calculations of the real parts and the meson-nucleon coupling constants, analyses of the data by recently developed numerical analytic continuation techniques, high-energy phenomenology, and evaluation of sum rules.