All arithmetical and logical operations in a computer/server configuration are addressed by its Central Processing Unit, or CPU. This hardware element is sometimes called the "brains" of the computer system also. The pace 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 quicker scripts and web apps shall be executed, although the performance of the latter depends upon other things as well - the read/write speed of the hard disk, the amount of physical memory, the network connectivity, and many others. All current CPUs have a number of cores, that work together. Therefore, the efficiency and the workload which a CPU can handle increase, because every core can process several tasks separately and several cores can handle one task that cannot be processed by 1 core.