All arithmetical and logical procedures inside a computer/server configuration are tackled by its Central Processing Unit, or CPU. This hardware part is typically called the "brains" of the personal computer as well. The rate at which the CPU runs system instructions is typically referred to as its speed which is measured in Hertz. The swifter the processing unit is, the more quickly scripts and web applications will be executed, although the performance of the latter depends upon other things as well - the read/write speed of the hard disk, the amount of physical memory, the network connectivity, etc. All new CPUs have numerous cores, that work together. Thus, the overall performance and the workload which a CPU can manage increase, as each core can process a number of tasks independently and a number of cores can handle one task that can't be processed by a single core.