COMPUTER HARDWARE BASICS: MOTHERBOARD, CPU AND MAIN MEMORY

MOTHERBOARD

A motherboard is the underlying circuit board of a computer. The central processing unit (CPU), Random Access Memory (RAM), hard drive(s), disk drives and optical drives are all plugged into interfaces on the motherboard. A video interface and sound card can be optionally built-in or added.

The motherboard can be thought of as the "backbone" of the computer.

CPU

The CPU is the brains of the computer. Sometimes referred to simply as the central processor, but more commonly called processor, the CPU is where most calculations take place. It is also the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system

Two typical components of a CPU are the following:

• The arithmetic logic unit (ALU), which performs arithmetic and logical operations.

• The control unit (CU), which extracts instructions from memory and decodes and executes them

MAIN MEMORY

There are two types of memory:

• RAM(RANDOM ACCESS MEMORY): It is the place in a computer where the operating system , application programs, and data in current use are kept so that they can be quickly reached by the computer's processor . RAM is much faster to read from and write to than the other kinds of storage in a computer, the hard disk, floppy disk, and CD-ROM. However, the data in RAM stays there only as long as your computer is running. When you turn the computer off, RAM loses its data. 
• ROM(READ ONLY MEMORY): It holds the program instructions and settings required to set up the computer. Once data has been written onto a ROM chip, it cannot be removed and can only be read.Unlike RAM, ROM retains its contents even when the computer is turned off.