All arithmetical and logical functions within a computer/server configuration are tackled by its Central Processing Unit, or CPU. This hardware component is oftentimes called the "brains" of the PC as well. The pace at which the CPU carries out system instructions is usually referred to as its speed and it is measured in Hertz. The faster the processing unit is, the speedier scripts and web applications shall be executed, although the overall performance of the latter depends upon other things as well - the read/write speed of the hard drive, the amount of physical memory, the network connectivity, etc. All new CPUs have several cores, which work together. Subsequently, the functionality and the workload that a CPU can handle increase, as every core can process various tasks separately and numerous cores can handle one task which can't be processed by a single core.