All arithmetical and logical operations inside a computer/server configuration are handled by its Central Processing Unit, or CPU. This hardware element is sometimes called the "brains" of the computer system as well. The rate at which the CPU executes system instructions is generally referred to as its speed which is measured in Hertz. The quicker the processing unit is, the more quickly scripts and web applications will be executed, even though the overall performance of the latter is determined by other things as well - the read/write speed of the hard disk drive, the amount of physical memory, the network connectivity, and so forth. All modern CPUs have numerous cores, that work together. Subsequently, the effectiveness and the workload that a CPU can manage increase, due to the fact that every core can process different tasks separately and a number of cores can handle one task that cannot be processed by a single core.