Spin physics at the Electron Ion Collider

The future Electron Ion Collider (EIC) will play a crucial role in our understanding of the structure of the building blocks of the visible universe, the proton and the neutron. We provide a concise presentation of the state of the art in the study of the polarized and three-dimensional structure of the nucleon, with particular emphasis on Transverse Momentum Distributions and the future studies at the EIC.