After a short introduction on specific features of hadron collisions at the LHC(proton-proton and heavy ions), particle identification in soft collisions is addressed taking examples from Alice and LHCb.
Turning to high transverse momentum interactions, the capability of ATLAS and CMS to identify reactions containing photons, electrons muons or taus is analyzed.
Some emphasis is put on the necessity, and means to identify particles at the trigger level.
Using the above signatures, plus some others (missing ET, identified B-jets), the role of particle id for some key physics discoveries (Higgs search, supersymmetry) is illustrated.