All arithmetical and logical operations inside a computer/server configuration are handled by its Central Processing Unit, or CPU. This hardware component is oftentimes called the "brains" of the personal computer too. The rate at which the CPU carries out 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 applications will be executed, although the performance of the latter is dependent upon other things as well - the read/write speed of the hard disk, the amount of physical memory, the network connectivity, etc. All current CPUs have a number of cores, which work together. Because of this, the functionality and the workload a CPU can manage increase, because every single core can process a number of tasks independently and numerous cores can handle a single task that cannot be processed by 1 core.