The motivations of the work that will be summarized in this presentation are to study the fundamental properties of the matter that surrounds us at a very fundamental level. More specifically I will focus on the structure of the neutron and the proton, the constituents of the atomic nucleus and of nuclear matter in general. The work that will be presented addresses the properties of nuclear matter under both simple conditions as studied using deep inelastic scattering of a lepton on a nucleon or with proton-proton collisions, and more extreme conditions such as those achieved in relativistic heavy ion collisions.  In more details, I will show results of photo-production of light particles in SIDIS processes at COMPASS, and QCD physics measurements of light and heavy quark particle production in both pp and heavy ion systems at RHIC and the LHC. The link between these results is that they can be described coherently with pQCD, or pQCD-inspired models. I will finish by discussing perspectives for studying the nuclear structure at the EIC focusing on the low-x regime.