CPU, which is often called just "processor", is an abbreviation for Central Processing Unit. That's the core of each and every laptop or computer or server, due to the fact that it executes all the calculations and logical input/output procedures. Although the performance of a site or an app depends on other things too, like the amount of physical memory or the connection of the web server, the rate at which a specific processor works determines how soon a program will be executed. Later-generation processors have a number of cores which can considerably increase their overall power and efficiency, since every single core can control several processes separately or several cores can handle 1 process that requires a sizeable computing power. Due to the fact that every core runs at a specific speed, this architecture can be looked at as a few individual processors cooperating.