All arithmetical and logical operations in a computer/server configuration are tackled by its Central Processing Unit, or CPU. This hardware part is occasionally called the "brains" of the personal computer as well. The pace at which the CPU runs system instructions is generally referred to as its speed which is measured in Hertz. The faster the processing unit is, the quicker scripts and web apps shall be executed, even though the general performance of the latter is dependent upon other things as well - the read/write speed of the hard disk drive, the amount of physical memory, the network connection, and many others. All modern CPUs have a number of cores, which work together. Because of this, the functionality and the workload that a CPU can take care of increase, due to the fact that every single core can process different tasks separately and numerous cores can handle 1 task that can't be processed by 1 core.