Fusion is a nuclear reaction that combines two light nuclei, producing energy; fusion reactions power stars like our sun. Producing energy from fusion would provide a carbon-free, clean, safe, and abundant source of electricity. Net energy production from fusion requires that the reactions occur in a ‘plasma’ hotter than the center of the sun. Raising the fuel to such temperatures requires a significant input of energy, and for decades experiments have been predominantly heated by external sources. A key milestone towards producing a significant energy output from fusion is to achieve a ‘burning plasma’ in which the fusion reactions themselves provide a majority of the heating, because this self-heating can be leveraged to greatly increase the energy output. Recent experiments on the National Ignition Facility, pursuing inertial fusion, have produced such burning plasmas in the laboratory for the first time. A subsequent experiment has since produced an ‘ignited’ plasma, in which the fusion self-heating surpasses all energy loss mechanisms for a period of time.