CPU, that is sometimes called just "processor", is an abbreviation for Central Processing Unit. That is the core of each laptop or computer or hosting server, as it executes all the calculations and logical input/output functions. Although the performance of an Internet site or an application depends on other things as well, including the amount of physical memory or the connectivity of the server, the rate at which a given processor operates determines how quick a program will be executed. Later-generation processors have numerous cores that can drastically increase their overall power and efficiency, because every core can control a number of processes independently or a few cores can take on a single process that needs a significant computing power. Due to the fact that each core works at a particular speed, this architecture can be looked at as a number of individual processors working together.