All arithmetical and logical functions in a computer/server configuration are tackled by its Central Processing Unit, or CPU. This hardware component is oftentimes called the "brains" of the computer system too. The rate at which the CPU carries out system instructions is usually referred to as its speed which is measured in Hertz. The swifter the processing unit is, the faster scripts and web apps will be executed, even though the performance of the latter is dependent upon other things also - the read/write speed of the hard disk, the amount of physical memory, the network connectivity, and so on. All newer CPUs have a number of cores, which work together. Therefore, the functionality and the workload which a CPU can tackle increase, due to the fact that each core can process various tasks individually and a number of cores can handle 1 task which cannot be processed by 1 core.