Ultraluminous Infrared Galaxies (ULIRGs) are a class of galaxies that emit an exceptionally high amount of infrared radiation, typically over 10^12 solar luminosities. This intense infrared output is primarily due to the presence of massive star formation and active galactic nuclei, which can be fueled by the merging of galaxies. These galaxies are often obscured by dust, making them difficult to observe in visible light. Instead, astronomers study them using infrared telescopes, such as the Hubble Space Telescope and the James Webb Space Telescope, to better understand their structure, formation, and the processes driving their luminosity.