All arithmetical and logical functions within a computer/server configuration are handled by its Central Processing Unit, or CPU. This hardware component is sometimes called the "brains" of the computer 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 swifter the processing unit is, the speedier scripts and web applications shall be executed, even though the performance of the latter depends on other things too - the read/write speed of the hard disk, the amount of physical memory, the network connectivity, and so forth. All current CPUs have numerous cores, which work together. Therefore, the overall performance and the workload a CPU can handle increase, due to the fact that every core can process various tasks separately and several cores can handle 1 task that cannot be processed by one core.