Abstract: Given that particles and their antiparticles are on similar footing theoretically, it is a puzzle that the universe contains much more matter than antimatter. Physicists have speculated that the matter-antimatter asymmetry might have been generated during the electroweak phase transition, when the Higgs field-- the thing that gives masses to elementary particles --went from being switched off to switched on shortly after the Big Bang. I will discuss the basic idea behind this framework, experimental probes, and challenges and opportunities for model-building, including a possible connection to dark matter.