The zoo of active galaxies: Seyferts, radio galaxies and quasars

The zoo of active galaxies is indeed very rich and diverse. In this talk, we will discuss briefly some of the more exotic types of active galaxies which are amongst the largest and most luminous objects known in the Universe, as well as the more mildly active Seyfert galaxies. We will discuss aspects of their source of energy, which is believed to be due to accretion on to a supermassive black hole, and their evolution with time.