All arithmetical and logical functions within a computer/server configuration are handled by its Central Processing Unit, or CPU. This hardware component is typically called the "brains" of the computer system as well. The rate at which the CPU runs system instructions is generally referred to as its speed which is measured in Hertz. The faster the processing unit is, the faster scripts and web apps will be executed, even though the general performance of the latter is dependent upon other things also - the read/write speed of the hard drive, the amount of physical memory, the network connectivity, and so on. All new CPUs have a number of cores, that work together. Subsequently, the efficiency and the workload that a CPU can handle increase, because every single core can process a number of tasks independently and numerous cores can handle one task that can't be processed by 1 core.