  One of the most important nonperturbative methods for solving QCD is
quantization at fixed light-front time, \tau = t+z/c -- Dirac's "Front Form".
The eigenvalues of the light-front QCD Hamiltonian predict the hadron spectrum
and the eigensolutions provide the light-front wavefunctions which describe
hadron structure. More generally, we show that the valence Fock-state
wavefunctions 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 U which
systematically incorporates the effects of higher quark and gluon Fock states.
We outline a method for computing the required potential from first principles
in QCD. The holographic mapping of gravity in AdS space to QCD, quantized at
fixed light-front time, yields the same light front Schr\"odinger equation; in
fact, the soft-wall AdS/QCD approach provides a model for the light-front
potential which is color-confining and reproduces well the light-hadron
spectrum. One also derives via light-front holography 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. The elastic and transition form factors of the
pion and the nucleons are found to be 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.
