Langevin dynamics is a simulation method used to model the behavior of particles in a fluid. It combines classical mechanics with random forces to account for the effects of thermal fluctuations. This approach is particularly useful in studying systems at the microscopic scale, such as biomolecules or colloidal particles, where the influence of the surrounding medium is significant. In Langevin dynamics, the motion of a particle is described by a set of equations that include both deterministic forces, like those from potential energy, and stochastic forces, which represent random collisions with surrounding molecules. This allows researchers to explore how particles move and interact over time in various environments.