All arithmetical and logical functions in a computer/server configuration are tackled by its Central Processing Unit, or CPU. This hardware component is usually called the "brains" of the computer also. The pace at which the CPU executes system instructions is usually referred to as its speed and it's measured in Hertz. The quicker the processing unit is, the speedier scripts and web applications will be executed, even though the efficiency of the latter depends upon other things also - the read/write speed of the hard drive, the amount of physical memory, the network connectivity, and many others. All new CPUs have numerous cores, that work together. As a result, the functionality and the workload a CPU can manage increase, as each and every core can process a number of tasks independently and numerous cores can handle one task that cannot be processed by a single core.