CPU, that's sometimes called just "processor", is an abbreviation for Central Processing Unit. That's the core of every personal computer or web server, due to the fact that it carries out all the calculations and logical input/output functions. Although the performance of an Internet site or an application is determined by other things also, including the amount of physical memory or the connection of the server, the pace at which a given processor works determines how quickly a program shall be executed. Later-generation processors have numerous cores that can seriously improve their overall power and efficiency, because each core can handle a number of processes separately or a few cores can handle 1 process that requires a sizeable computing power. Since every single core works at a specific speed, this architecture can be looked at as a number of independent processors working together.