  The AdS/CFT correspondence between theories in AdS space and conformal field
theories in physical space-time provides an analytic, semi-classical,
color-confining model for strongly-coupled QCD. The soft-wall AdS/QCD model
modified by a positive-sign dilaton metric leads to a remarkable one-parameter
description of nonperturbative hadron dynamics at zero quark mass, including a
zero-mass pion and a Regge spectrum of linear trajectories with the same slope
in orbital angular momentum $L$ and radial quantum number $n$ for both mesons
and baryons. One also predicts the form of the non-perturbative effective
coupling $\alpha_s^{AdS}(Q)$ and its $\beta$-function which agrees with the
effective coupling $\alpha_{g_1}$ extracted from the Bjorken sum rule.
Light-front holography, which connects the fifth-dimensional coordinate of AdS
space $z$ to an invariant impact separation variable $\zeta$, allows one to
compute the analytic form of the frame-independent light-front wavefunctions,
the fundamental entities which encode hadron properties as well as decay
constants, form factors, deeply virtual Compton scattering, exclusive heavy
hadron decays and other exclusive scattering amplitudes. One thus obtains a
relativistic description of hadrons in QCD at the amplitude level with
dimensional counting for hard exclusive reactions at high momentum transfer. As
specific examples we discuss the behavior of the pion and nucleon form factors
in the space-like and time-like regions. We also review the phenomenology of
exclusive processes including some anomalous empirical results.
