Collective flow and hydrodynamics in large and small systems at the LHC

In this article, we briefly review the recent progress on collective flow and hydrodynamics in large and small systems at the Large Hadron Collider (LHC), which includes the following topics: extracting the QGP viscosity from the flow data, initial-state fluctuations and final-state correlations at 2.76 A TeV Pb-Pb collisions, correlations, and collective flow in high-energy p-Pb and p-p collisions.