  The AdS/CFT correspondence has led to important insights into the properties
of quantum chromodynamics even though QCD is a broken conformal theory. A
holographic model based on a truncated AdS space can be used to obtain the
hadronic spectrum of light $q \bar q, qqq$ and $gg$ bound states. Specific
hadrons are identified by the correspondence of string modes with the dimension
of the interpolating operator of the hadron's valence Fock state, including
orbital angular momentum excitations. The predicted mass spectrum is linear $M
\propto L$ at high orbital angular momentum. Since only one parameter, the QCD
scale $\Lambda_{QCD}$, is introduced, the agreement with the pattern of
physical states is remarkable. In particular, the ratio of $\Delta$ to nucleon
trajectories is determined by the ratio of zeros of Bessel functions. One can
also use the extended AdS/CFT space-time theory to obtain a model for hadronic
light-front wavefunctions, thus providing a relativistic description of hadrons
in QCD at the amplitude level. The model wavefunctions display confinement at
large inter-quark separation and conformal symmetry at short distances. In
particular, the scaling and conformal properties of the LFWFs at high relative
momenta agree with perturbative QCD. These AdS/CFT model wavefunctions could be
used as an initial ansatz for a variational treatment of the light-front QCD
Hamiltonian. Hadron form factors in both the space-like and time-like regions
are also predicted.
