CPU, that is frequently called just "processor", is an abbreviation for Central Processing Unit. That is the core of every PC or hosting server, due to the fact that it runs all of the calculations and logical input/output procedures. Although the performance of a site or an application is determined by other things also, like the amount of physical memory or the online connectivity of the web server, the rate at which a certain processor operates determines how fast a program shall be executed. Later-generation processors have numerous cores that can seriously boost their overall power and efficiency, as every core can take on several processes individually or a few cores can control 1 process which requires a substantial processing power. As every core functions at a particular speed, this architecture can be seen as numerous individual processors working together.