All arithmetical and logical operations inside a computer/server configuration are addressed by its Central Processing Unit, or CPU. This hardware component is oftentimes called the "brains" of the PC as well. The pace at which the CPU carries out system instructions is generally referred to as its speed which is measured in Hertz. The quicker the processing unit is, the quicker scripts and web apps will be executed, though the performance of the latter is dependent upon other things too - the read/write speed of the hard drive, the amount of physical memory, the network connectivity, etc. All new CPUs have a number of cores, which work together. Subsequently, the overall performance and the workload a CPU can handle increase, since every single core can process a number of tasks separately and several cores can handle one task which cannot be processed by one core.