Droplet coalescence is commonly encountered in nature and is also relevant for various technologies, such as Microfluidics. In this presentation, I will discuss the details of molecular dynamics simulation and the Coarse-Grained method. Moreover, I will present our results on the coalescence of surfactant-laden water droplets, which have been obtained by means of a coarse-grained (CG) force-field. In particular, I will discuss the details of the coalescence mechanism and the bridge growth dynamics.