Quantum chromodynamics has been extremely successful in describing many high-energy experiments with the use of universal parton distribution functions. PDFs of the free proton are well-constrained by experimental data, but nuclear PDFs require further elaboration. Three ingredients are necessary to theoretically obtain nuclear PDFs: (1) an account of the nuclear momentum distribution that accounts for the latest phenomenology of short range correlations; (2) a model of how bound nucleons are modified at a partonic level due to immersion in the nuclear medium; and (3) the application of QCD evolution to connect the low momentum transfer scales where the first two ingredients are obtained to the high momentum transfer scales relevant to the LHC and anticipated EIC. These three ingredients will be elaborated in detail, and an application of the obtained nuclear PDFs to proton-nucleus collisions at the LHC will be given.