All arithmetical and logical procedures in a computer/server configuration are tackled by its Central Processing Unit, or CPU. This hardware part is oftentimes called the "brains" of the PC also. The rate at which the CPU completes system instructions is usually referred to as its speed and it's measured in Hertz. The swifter the processing unit is, the quicker scripts and web applications shall be executed, though the performance of the latter depends on other things also - the read/write speed of the hard drive, the amount of physical memory, the network connectivity, and so forth. All modern CPUs have numerous cores, that work together. For that reason, the functionality and the workload which a CPU can tackle increase, due to the fact that every single core can process a number of tasks independently and several cores can handle one task that cannot be processed by 1 core.