Complex Monge-Ampère equations have been one of the most powerful tools in Kaehler geometry since Aubin and Yau’s classical works. In recent years degenerate complex Monge-Ampère equations have been intensively studied by many authors in relation to the Minimal Model Program. Pluripotential methods play a crucial role when dealing with such degenerate Monge-Ampère equations. I will introduce some basic notions in pluripotential theory and I will give an alternative proof of the Yau’s proof of the Calabi’s conjecture using pluripotential techniques.