XMM-Newton is a space observatory launched by the European Space Agency in 1999. It is designed to study X-rays emitted by high-energy objects in the universe, such as black holes, neutron stars, and supernova remnants. The observatory features three X-ray telescopes and is capable of capturing detailed images and spectra of celestial sources. The name XMM stands for "X-ray Multi-Mirror," reflecting its advanced technology that allows it to observe a wide range of X-ray wavelengths. XMM-Newton has contributed significantly to our understanding of cosmic phenomena and continues to provide valuable data for astronomers worldwide.