Laser pumping is the fundamental process of supplying external energy to a laser gain medium to achieve population inversion, a non-equilibrium distribution of atoms or molecules critical for stimulated emission and laser oscillation. As a core concept and methodological area in laser physics and optical engineering, it investigates various energy transfer mechanisms (such as optical, electrical, or chemical excitation), the dynamics of energy levels within the gain medium, and methods for optimizing the efficiency and spatial/temporal characteristics of energy deposition required to sustain optical gain. Its significance is paramount, constituting the essential prerequisite for achieving stimulated emission and enabling the generation of coherent light.