Active galaxies are galaxies that emit high levels of energy compared to normal galaxies. This high level of energy is believed to be produced by supermassive black holes at the centers of these galaxies. These black holes are accreting large amounts of gas and dust, generating intense radiation and jets of high-energy particles that can be observed across different wavelengths of the electromagnetic spectrum. There are several types of active galaxies, including Seyfert galaxies, radio galaxies, and quasars. These galaxies exhibit unique characteristics that distinguish them from normal galaxies, such as strong emission lines in their spectra, radio emissions, and rapid variability in their brightness. Studying active galaxies can provide valuable insights into the processes of black hole accretion, galaxy evolution, and the distribution of matter and energy in the universe. Researchers use a combination of observational data from telescopes and theoretical models to understand the mechanisms that drive the activity in these galaxies and their impact on their surroundings.