A quasar is a star-like radio source with an observed redshift that indicates extremely large distance from the Earth.
Quasars are the most luminous objects in the sky.
Because of their great distance from us, they are often rather unimpressive in appearance. A pulsar is an object that emits radiation in the form of rapid pulses with a characteristic pulse period and duration. Charged particles, accelerated by the magnetic field of a rapidly rotating neutron star, flow along the magnetic field lines, producing radiation that beams outward as the star spins on its axis.