CPU, that's frequently called just "processor", is an abbreviation for Central Processing Unit. That is the core of every personal computer or hosting server, as it carries out all the calculations and logical input/output procedures. Even though the performance of a website or an app relies upon other things also, like the amount of physical memory or the connectivity of the hosting server, the pace at which a particular processor works determines how quickly an application shall be executed. Later-generation processors have a number of cores that can seriously improve their overall power and efficiency, since every core can take care of a number of processes separately or a few cores can handle one process that needs a significant processing power. Due to the fact that each core operates at a specific speed, this architecture can be seen as a few individual processors cooperating.