Laser simulation is a computational methodology employing numerical models and algorithms to represent and analyze the complex interactions of laser radiation with various forms of matter, including plasmas, solids, and gases, often under extreme conditions. This approach investigates fundamental phenomena such as laser-plasma coupling, high-energy density physics, nonlinear optical effects, and material response to intense light, providing crucial predictive capabilities and enabling the design and interpretation of experiments in fields like inertial confinement fusion, advanced accelerators, and laser-based material science.