High-precision measurements by the ATLAS Collaboration are presented of inclusive Formula omitted, Formula omitted and Formula omitted ( Formula omitted) Drell-Yan production cross sections at the LHC. The data were collected in proton-proton collisions at Formula omitted with an integrated luminosity of Formula omitted. Differential Formula omitted and Formula omitted cross sections are measured in a lepton pseudorapidity range Formula omitted. Differential Formula omitted cross sections are measured as a function of the absolute dilepton rapidity, for Formula omitted, for three intervals of dilepton mass, Formula omitted, extending from 46 to Formula omitted. The integrated and differential electron- and muon-channel cross sections are combined and compared to theoretical predictions using recent sets of parton distribution functions. The data, together with the final inclusive Formula omitted scattering cross-section data from H1 and ZEUS, are interpreted in a next-to-next-to-leading-order QCD analysis, and a new set of parton distribution functions, ATLAS-epWZ16, is obtained. The ratio of strange-to-light sea-quark densities in the proton is determined more accurately than in previous determinations based on collider data only, and is established to be close to unity in the sensitivity range of the data. A new measurement of the CKM matrix element Formula omitted is also provided.