A 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). 
I will pay special attention to the so-called Transverse Momentum 
Dependent parton distribution and fragmentation
functions. Jefferson Lab 12 will play crucial role in experimental 
exploration of hadron structure. I will explain details of the program 
and show the potential of future measurements. I will also discuss 
future plans beyond Jefferson Lab 12 at a proposed Electron-Ion Collider.