[en] The heavy quark i.e., charm and bottom quarks, are produced in hard scattering processes at the initial stages of the heavy-ion collisions and pass through the whole space-time history of the transient matter. During the evaluation they can interact with the medium and lose energy via both inelastic processes (radiative energy loss) and elastic scatterings (collisional energy loss). The partonic energy loss mechanism in the deconfined QCD medium has been developed remarkably in recent years. Experimentally, it can be probed by measuring the high-p_T hadrons emanating from ultrarelativistic heavy ion collisions