CPU, which is often called just "processor", is an abbreviation for Central Processing Unit. That's the core of any PC or server, due to the fact that it performs each of the calculations and logical input/output procedures. Even though the performance of a website or an application depends on other things too, including the amount of physical memory or the online connectivity of the web server, the rate at which a specific processor performs determines how quick an application will be executed. Later-generation processors have numerous cores that can considerably increase their overall power and efficiency, since each core can handle a variety of processes independently or several cores can control one process that needs a significant processing power. Because each core operates at a specific speed, this architecture can be viewed as a number of independent processors working together.