All arithmetical and logical operations within 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 executes system instructions is commonly referred to as its speed and it is measured in Hertz. The swifter the processing unit is, the faster scripts and web apps shall be executed, though the overall performance of the latter is determined by other things also - the read/write speed of the hard drive, the amount of physical memory, the network connection, etc. All newer CPUs have a number of cores, which work together. Subsequently, the functionality and the workload a CPU can handle increase, since each and every core can process different tasks independently and several cores can handle a single task which can't be processed by 1 core.