CPU, that's frequently called just "processor", is an abbreviation for Central Processing Unit. That's the core of each and every PC or hosting server, because it carries out each of the calculations and logical input/output functions. Despite the fact that that the performance of a site or an app depends on other things too, such as the amount of physical memory or the online connectivity of the hosting server, the rate at which a specific processor works determines how soon a program will be executed. Later-generation processors have numerous cores which can significantly improve their overall power and efficiency, due to the fact that every single core can control a variety of processes individually or several cores can deal with a single process which needs a significant computing power. Because every single core functions at a certain speed, this architecture can be viewed as a number of independent processors working together.