I would like to know how vehicle routing software optimizes routes? In demos of this software, they provide the optimal (or a good) route in just a few seconds or minutes with several nodes (maybe 50 or 100). What are the main algorithms used to solve this type of problem? Moreover, in software, it is possible to define the location of nodes by clicking on the map and it adds another step to determine the distance of nodes. However, the software can easily solve the problem.