  The holographic mapping of gravity in AdS space to QCD, quantized at fixed
light-front time, provides a precise relation between the bound-state
amplitudes in the fifth dimension of AdS space and the boost-invariant
light-front wavefunctions describing the internal structure of hadrons in
physical space-time. In particular, the elastic and transition form factors of
the pion and the nucleons are well described in this framework. The light-front
AdS/QCD holographic approach thus gives a frame-independent first approximation
of the color-confining dynamics, spectroscopy, and excitation spectra of
relativistic light-quark bound states in QCD. More generally, we show that the
valence Fock-state wavefunctions of the eigensolutions of the light-front QCD
Hamiltonian satisfy a single-variable relativistic equation of motion,
analogous to the nonrelativistic radial Schr\"odinger equation, with an
effective confining potential which systematically incorporates the effects of
higher quark and gluon Fock states. The proposed method to compute the
effective interaction thus resembles the two-particle-irreducible functional
techniques used in quantum field theory.
