The Compact Muon Solenoid (CMS) detector is one of the two multi-purpose experiments operating at the CERN Large Hadron Collider (LHC). Many aspects of its broad physics program depend on the ability to trigger, reconstruct and identify events with electrons and photons in the final state.
The full process of electron and photon reconstruction in CMS is presented in this contribution. Reconstruction algorithms, starting from tracker hits and energy deposits in the electromagnetic calorimeter, are described. Current identification algorithms are compared with the previous ones, focusing on the improvements achieved in obtaining the ultimate precision in Run II energy measurements.
Particular attention is given to the evolution of detector conditions and identification criteria to- wards the different years of data-taking. The contribution covers extensively the results from 2016 and 2017 dataset of LHC, with quick highlights from the ongoing 2018 data-taking.