  Deep Inelastic Scattering would be brought into the unexplored TeV regime by
the the proposed Large Hadron Electron Collider at CERN. Its rich physics
program, includes both precision Standard Model measurements to complement LHC
physics as well as studies of QCD in the high energy limit. The present
proceeding reports on studies included in the updated LHeC Conceptual Design
Report. We study the impact of LHeC simulated data on Parton Distribution
Functions uncertainties. We also assess the LHeC potential to allow the
determination of the strong coupling constant $\alpha_{S}$, at per-mille level
as well as to disentangle between various scenarios of small-$x$ QCD.
