Definition: microprocessor

A central processing unit (CPU) on a single chip (integrated circuit). The microprocessor term originated in the 1970s, but today, all CPUs are microprocessors, whether in desktops, laptops, servers, tablets or smartphones (see multicore).

CPU, MPU and MP = Processor
The terms central processing unit (CPU), microprocessor unit (MPU) and microprocessor (MP) are synonymous. The MP acronym is sometimes spelled "uP" or "µP" (lower case "m" in Greek is a "µ").

From 8-Bit to 64-Bit
The earliest microprocessors were created by Texas Instruments, Intel and Scotland-based Pico Electronics, but which was first has been debated. First-generation 8-bit microprocessor families were Intel's 8080, Zilog's Z80, Motorola's 6800 and Rockwell's 6502.

Today, the 32-bit and 64-bit microprocessors found in workstations and servers are x86, POWER and SPARC, while ARM leads the mobile market. The chips used in toys, appliances, vehicles and myriad other products are 8-, 16- and 32-bit microcontrollers, which include the microprocessor (see microcontroller). All together billions of microprocessors are made and shipped each year. See chip, embedded system, process technology, 16-bit computing, 32-bit computing and 64-bit computing.

The 386 Microprocessor

No technology is more incredible than the microprocessor. This older 386 chip contains a mere 275,000 transistors, and some slight detail can be seen. Contemporary chips at this magnification show up as a sea of gray. See chip. (Image courtesy of Intel Corporation.)

From Two Thousand to Nineteen Billion

This is only a sampling of the number of transistors on a chip. Other brands have similar transistor counts.