eRHIC: The electron ion collider at BNL

Addition of a high intensity and high energy polarized electron/positron beam facility to the already existing Relativistic Heavy Ion Collider (RHIC) complex so that electrons/positron from that facility could collide with the RHIC hadron beams, would significantly enhance RHIC's ability to explore fundamental and universal aspects of QCD. We present here the high lights of the physics program that could result as a result of such a RHIC upgrade. (orig.)