CPU, that's sometimes called just "processor", is an abbreviation for Central Processing Unit. That's the core of each and every personal computer or web server, due to the fact that it carries out each of the calculations and logical input/output operations. Though the performance of a website or an app relies on other things too, including the amount of physical memory or the connectivity of the hosting server, the pace at which a certain processor works determines how quickly an app will be executed. Later-generation processors have multiple cores which can seriously improve their overall power and efficiency, as each and every core can take care of a variety of processes separately or a number of cores can take care of one process which needs a substantial processing power. Because each and every core operates at a certain speed, this architecture can be seen as a number of independent processors cooperating.