A great deal of experimental and theoretical progress has been achieved in our understanding of hadron structure in recent decades. I will discuss our current understanding of hadron structure from the point of view of Quantum Chromodynamics, the theory that describes the hadron as dynamical system of partons (quarks and gluons). Jefferson Lab 12 will play crucial role in experimental measurements of hadron structure. I will explain details of the program and show the potential of future measurements. I will also discuss future of nuclear physics beyond Jefferson Lab 12 at a proposed Electron-Ion Collider.