All arithmetical and logical operations inside a computer/server configuration are tackled by its Central Processing Unit, or CPU. This hardware part is occasionally called the "brains" of the PC also. The pace at which the CPU completes system instructions is typically referred to as its speed and it's measured in Hertz. The swifter the processing unit is, the quicker scripts and web apps will be executed, although the efficiency of the latter is determined by other things also - the read/write speed of the hard disk, the amount of physical memory, the network connectivity, and so on. All new CPUs have numerous cores, which work together. Because of this, the efficiency and the workload which a CPU can handle increase, as each and every core can process various tasks independently and numerous cores can handle a single task which can't be processed by 1 core.