All arithmetical and logical procedures in a computer/server configuration are addressed by its Central Processing Unit, or CPU. This hardware component is oftentimes called the "brains" of the personal computer as well. The rate at which the CPU runs system instructions is also referred to as its speed and it is measured in Hertz. The faster the processing unit is, the faster scripts and web programs shall be executed, even though the efficiency of the latter is determined by other things too - the read/write speed of the hard drive, the amount of physical memory, the network connectivity, and so forth. All modern CPUs have a number of cores, that work together. Subsequently, the efficiency and the workload a CPU can handle increase, since every single core can process different tasks separately and numerous cores can handle a single task which cannot be processed by 1 core.