All arithmetical and logical functions in a computer/server configuration are handled by its Central Processing Unit, or CPU. This hardware element is oftentimes called the "brains" of the personal computer as well. The pace at which the CPU executes system instructions is usually referred to as its speed and it's measured in Hertz. The faster the processing unit is, the speedier scripts and web apps will be executed, though the efficiency 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 multiple cores, which work together. As a result, the effectiveness and the workload which a CPU can tackle increase, because each and every core can process various tasks independently and numerous cores can handle 1 task that can't be processed by 1 core.