Central Processing Unit(CPU)

A CPU (Central Processing Unit) is an important part of every computer. The CPU is like the brain; its job is to carry out instructions and calculations.
The CPU is an electronic machine that works on a list of things to do. It reads the list, one item at a time, doing each instruction in order. A list of instructions that a CPU can read is a computer program. A machine that can perform the job of a CPU is often called a Turing machine by mathematicians.
Here are some of the basic things a CPU can do:
Add two numbers together
Test to see if one number is larger than another
Move a number from one place to another
Get a number from memory
Jump to another place in the instruction list
Even very complicated programs can be made by combining many simple instructions like these. This is possible because each instruction takes a very small time to happen. Many CPUs today can do more than 1 billion instructions in a single second. In general, the more a CPU can do in a given time, the faster it is. One way to measure a processor's speed is MIPS. Flops and CPU clock speed (usually measured in gigahertz) are also ways to measure how much work a processor can do in a certain time.
A CPU is built out of logic gates; it has no moving parts. The CPU of a computer is connected electronically to other parts of the computer, like the video card, or the BIOS. A computer program can control these peripherals by reading or writing numbers to special places in the computer's memory.