Post-Keynesian economics is a unique school of thought within economics that differs from traditional approaches. It includes various strands like fundamentalist Keynesians, Kaleckians, Kaldorians, Sraffians, and institutionalists. Despite their differences, they share common features that set them apart. The development of post-Keynesian economics can be traced back to the works of Michal Kalecki and John Maynard Keynes. Currently, post-Keynesian economics offers an alternative perspective to mainstream orthodox economics.