Physics today consists of models trying to describe properties of the reality in the most simple and logical way. In order to test the validity of any theoretical model of a physical process, it must be compared with real measurements by a experiment. The theoretical assumptions and model descriptions are implemented into a Monte Carlo (MC) computer program that randomly generate events according to some preset rules. The generated events are then run through a simulation program that should describe the detector response, which then can be compared with real data.