All arithmetical and logical functions within a computer/server configuration are addressed by its Central Processing Unit, or CPU. This hardware element is oftentimes called the "brains" of the PC as well. The rate at which the CPU executes system instructions is commonly referred to as its speed and it is measured in Hertz. The quicker the processing unit is, the more quickly scripts and web programs shall be executed, though the efficiency of the latter is determined by other things too - the read/write speed of the hard disk, the amount of physical memory, the network connection, and so on. All newer CPUs have numerous cores, which work together. Therefore, the functionality and the workload a CPU can take care of increase, since each core can process several tasks separately and numerous cores can handle one task which cannot be processed by 1 core.