All arithmetical and logical procedures in a computer/server configuration are addressed by its Central Processing Unit, or CPU. This hardware part is typically called the "brains" of the computer too. The pace at which the CPU completes system instructions is also referred to as its speed and it is measured in Hertz. The faster the processing unit is, the speedier scripts and web apps will be executed, even though the performance of the latter is determined by other things too - the read/write speed of the hard disk drive, the amount of physical memory, the network connection, etc. All current CPUs have numerous cores, that work together. Therefore, the overall performance and the workload that a CPU can manage increase, because every single core can process different tasks independently and a number of cores can handle one task which can't be processed by a single core.