Brodsky's research areas span many areas of high-energy and nuclear theoretical physics, especially the quark-gluon structure of hadrons and novel effects in quantum chromodynamics; fundamental problems in atomic, nuclear, and high energy physics; precision tests of quantum electrodynamics, light-front quantization; nonperturbative and perturbative methods in quantum field theory. In 1970 Brodsky and his collaborators, Tom Kinoshita and Hidezumi Terazawa, initiated the field of two-photon processes. In 1973 Brodsky and G. Farrar developed “dimensional counting rules” for hard exclusive processes, extending earlier work on the quark interchange model by Brodsky, Blankenbecler, and Gunion. In 1979, Brodsky and G. P. Lepage derived the theory of hard exclusive processes in QCD, including factorization theorems and evolution equations for meson and baryon distribution amplitudes. In 1985 Brodsky and H. C. Pauli developed the discretized light-cone quantization (DLCQ) method for solving quantum field theories. Brodsky has also contributed to precision tests of quantum electrodynamics and novel effects in atomic physics, including anti-hydrogen production and radiation amplitude null zones. Brodsky and his collaborators have also developed the theory underlying novel QCD properties such as color transparency, hidden color, reduced nuclear amplitudes, and intrinsic charm; theoretical tools such as light-front wavefunctions, commensurate scale relations, renormalization scale-setting, and jet measures; and applications of QCD to deeply virtual Compton scattering, diffractive deep inelastic scattering and other hard diffractive phenomena, shadowing and antishadowing of nuclear reactions, high energy photon-photon collisions, leading-twist single-spin asymmetries, and higher twist reactions. Most recently he has been collaborating with Guy F. de Téramond on the insights into the QCD spectra and hadron light-front wavefunctions which can be obtained from the AdS/CFT correspondence.