A processor is the logic circuitry that responds to and processes the basic instructions that drive a computer.
The term processor has generally replaced the term central processing unit (CPU) that has been used in early generations of computers. The processor in a personal computer or embedded in small devices is often called a microprocessor.
A microprocessor is designed to perform arithmetic and logic operations that make use of small number-holding areas called registers. Typical microprocessor operations include the following:
- comparing two numbers,
- fetching numbers from one area to another.
There is one important law related to processors and microprocessors.
Moore's Law and multi-core processors
Microprocessors were invented in late 1960s and early 1970s.
Since the early 1970s, the increase in processing capacity of evolving microprocessors has been known to generally follow Moore's Law. Moore's Law suggests that the complexity of an integrated circuit, with respect to minimum component cost, doubles every 18 months.Keeping up with Moore's Law is becoming increasingly challenging as chip-making technologies approach the physical limits of the technology. While adding extra processors to the computer, also known as symmetric multiprocessing has been known in servers since the early 1990s, dual and more core processors in workstations are becomming popular just recently.
In 2005, the first mass-market dual-core processors were announced and as of 2007 dual-core processors are widely used in servers, workstations and PCs while quad-core processors are now available for high-end applications in both the home and professional environments.