All arithmetical and logical functions in a computer/server configuration are tackled by its Central Processing Unit, or CPU. This hardware element is sometimes called the "brains" of the personal computer too. The pace at which the CPU runs system instructions is generally referred to as its speed which is measured in Hertz. The quicker the processing unit is, the quicker scripts and web apps shall be executed, even though the general performance of the latter depends upon other things too - the read/write speed of the hard disk drive, the amount of physical memory, the network connectivity, and so forth. All newer CPUs have numerous cores, which work together. Thus, the effectiveness and the workload a CPU can take care of increase, as each core can process a number of tasks separately and numerous cores can handle one task that can't be processed by 1 core.