The PSO belongs to the class of direct search methods used to find an optimal solution to an objective function (aka fitness function) in a search space. Direct search methods are usually derivative-free, meaning that they depend only on the evaluation of the objective function. The particle swarm optimization algorithm is simple, in the sense that the even the basic form of the algorithm yields results, it can be implemented by a programmer in short duration, and it can be used by anyone with an understanding of objective functions and the problem at hand without needing an extensive background in mathematical optimization theory.