This document provides an overview of post-Keynesian economics. It defines post-Keynesian economics, outlines some of its key characteristics such as its focus on effective demand and historical dynamics. It also describes some of the different strands within post-Keynesian theory, including Michal Kalecki's emphasis on imperfect competition and class division. Additionally, it summarizes theories around post-Keynesian income distribution in corporate economies developed by Robinson, Kaldor and Pasinetti, and post-Keynesian employment analysis based on the principle of effective demand determining labor-hire decisions.