All arithmetical and logical procedures inside a computer/server configuration are handled by its Central Processing Unit, or CPU. This hardware component is usually called the "brains" of the computer system as well. The rate at which the CPU executes system instructions is generally referred to as its speed and it is measured in Hertz. The speedier the processing unit is, the speedier scripts and web programs will be executed, though the general performance of the latter is determined by other things too - the read/write speed of the hard disk, the amount of physical memory, the network connection, and many others. All new CPUs have multiple cores, that work together. Thus, the effectiveness and the workload that a CPU can tackle increase, due to the fact that each and every core can process different tasks individually and a number of cores can handle one task that cannot be processed by one core.