Magnetars are a special class of neutron stars with ultra-strong magnetic fields, the strongest of any object in the observable universe, approximately a trillion times stronger than the most powerful permanent magnets ever created on Earth. Neutron stars are the remnant cores of massive stars formed at the end of their lives, possessing a mass greater than the Sun and compressed to the size of a city, making them natural laboratories for studying extreme physical phenomena. Magnetars, as previously thought, can come in different types. One possibility is an exploding object orbiting a black hole surrounded by a disk of material. Another possibility is a pair of rotating neutron stars whose magnetospheres periodically interact, creating a cavity where eruptions can occur. Magnetars are estimated to be active for about 10,000 years before settling down, so they could be found where a firestorm of star formation is occurring. However, this does not seem to be the case for all magnetars.