A CentralProcessingUnit is the hardware within a computer that carries out the instructions of a computer program by performing the basic arithmetical, logical, control and input/output operations of the system.
Early CPUs were custom-designed as a part of a larger, sometimes one-of-a-kind, computer. However, this method of designing custom CPUs for a particular application has largely given way to the development of mass-produced processors that are made for many purposes.
This standardization began in the era of discrete transistor mainframes and minicomputers, and has rapidly accelerated with the popularization of the IntergratedCircuit. Both the miniaturization and standardization of CPUs have increased the presence of digital devices in modern life far beyond the limited application of dedicated computing machines. Modern microprocessors appear in everything from automobiles to cell phones and even children's toys.