All arithmetical and logical procedures within a computer/server configuration are addressed by its Central Processing Unit, or CPU. This hardware part is typically called the "brains" of the computer system as well. The rate at which the CPU completes system instructions is usually referred to as its speed and it is measured in Hertz. The swifter the processing unit is, the faster scripts and web applications shall be executed, even though the general performance of the latter is dependent upon other things too - the read/write speed of the hard disk drive, the amount of physical memory, the network connectivity, and many others. All current CPUs have multiple cores, that work together. Subsequently, the functionality and the workload which a CPU can take care of increase, due to the fact that every core can process different tasks separately and numerous cores can handle 1 task which can't be processed by a single core.