A crucial step towards identifying interesting events produced in pp collisions is to correctly identify and measure the numerous particles that are typically produced in such collision events. The combination of information read out from all channels of the various subdetectors of the CMS detector, to identify the type, energy, momentum, and trajectory of the final-state stable particles, that are produced as a result of pp collision events and leave an identifiable signature in at least one of the subdetectors, is referred to as physics object reconstruction. Neutrinos (and other possible BSM particles) do not leave signatures on the detectors, and are indirectly identifiable by balancing the initial and final momenta in the transverse plane. As quarks hadronise immediately after the collision, the clusters of final-state hadrons are reconstructed as jets. Heavier particles like the top quark and tau lepton as well as massive bosons are not detected directly, but their presence can usually be inferred by reconstructing their decay products.