Theoretical calculations for hadronic high energy process are predominantly based on QCD factorization framework which allows separating the perturbatively calculable parton level cross-sections and non-perturbative parton distribution functions (PDFs) describing the structure of hadrons (nucleons or nuclei). Because of the non-perturbative nature PDFs are typically determined from fits to experimental data. In this presentation, I provide an introduction to global analysis of collinear PDFs with the emphasis on the nuclear PDFs (nPDFs). I also provide a brief review of the available nPDFs and recent results as well as comment on the connection with the Electron-Ion Collider (EIC).
