Quantum Chromodynamics (QCD) is the theory describing the strong interaction between subatomic particles, which is responsible for generating the mass of the visible universe (the Higgs contribution is negligible). Yet, the strength of the interaction makes the phenomenology elusive. We still do not know how quarks and gluons – the fundamental building blocks of matter – are confined inside the nucleons (protons and neutrons) that make up atomic nuclei. However, following in the footsteps of the 12 GeV program at Jefferson Lab and the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Lab, the Electron-Ion Collider (EIC) will be the next-generation facility for QCD providing us with the experimental tools needed to create a 3D image of the proton and to understand the origins of its spin. It will also, for the first time, give us view of the gluon field inside a nucleus. We will learn about its spatial distribution and “lumpiness,” and explore the dramatic rise in the density of low-momentum gluons (the carriers of the strong force) and study the onset of saturation. This talk will focus on what we can learn from electron scattering experiments at the QCD frontier, and also describe some of the novel detector systems that are being developed to achieve these goals.