All arithmetical and logical functions inside a computer/server configuration are tackled by its Central Processing Unit, or CPU. This hardware element is occasionally called the "brains" of the personal computer too. The pace at which the CPU runs system instructions is generally referred to as its speed and it's measured in Hertz. The speedier the processing unit is, the speedier scripts and web programs will be executed, though the efficiency of the latter depends on other things also - the read/write speed of the hard drive, the amount of physical memory, the network connection, and many others. All newer CPUs have multiple cores, which work together. Thus, the functionality and the workload a CPU can tackle increase, due to the fact that each core can process various tasks separately and several cores can handle a single task that cannot be processed by a single core.