All arithmetical and logical functions inside a computer/server configuration are tackled by its Central Processing Unit, or CPU. This hardware element is oftentimes called the "brains" of the computer system as well. The rate at which the CPU completes system instructions is typically referred to as its speed and it's measured in Hertz. The speedier the processing unit is, the faster scripts and web applications shall be executed, even though the overall performance of the latter is determined by other things also - the read/write speed of the hard drive, the amount of physical memory, the network connection, and so on. All newer CPUs have a number of cores, which work together. Thus, the effectiveness and the workload which a CPU can tackle increase, as each core can process various tasks independently and numerous cores can handle 1 task which cannot be processed by 1 core.