Understanding a Computer

by Alden Smith

In America today, 3 of 5 children aged 3 to 17 have access to a computer, and 43% had internet access. The number of computers in homes has jumped astronomically in just a few short years, yet many people are baffled by computers, how they work, and how they access the internet. Baby boomers are the fastest growing segment of the population getting computers for the first time, with more people retiring and wishing to keep in touch with families and friends. Yet even with all these people having computers, many have no clue how they work, or even the capabilities they offer us today. Here, we will take a basic course in computers to help the uninformed better understand that magic black box full of surprises.

How A Computer Works

A computer is made up of several units, each dependent on the other. They are:

1. The Central Processing Unit, or CPU
   
2. Main memory, called Random Access Memory, or RAM
   
3. Read Only Memory, or ROM
   
4. Ports and controllers
   
5. Input devices, such as keyboard and mouse
   
6. Secondary storage units, such as hard disk, floppy
   drives, and CD-ROM's
   
7. Buses
   
8. The operating system, or OS

Each of these units depends on one another to make the computer do what you want it to do.

Let's look at each one:

1. The CPU is the "brain" of the computer. It contains
   two parts - the control unit, and the arithmetic/logic
   unit. The extensive electronic circuitry of the CPU
   executes stored program instructions.
2. RAM is what gives the computer its agility in
   performing operations. Think of RAM in this way -
   it is much like pouring water through a hose. The
   larger the hose, the faster the water flows. The more
   RAM your system has, the faster it is able to perform
   whatever operation you ask of it.
3. ROM, unlike RAM, retains memory after the computer
   is turned off. It stores the basic instructions required
   to boot the computer and start up the operating system.
4. Ports and controllers allows the computer to
   communicate with other peripherals in the system. An
   example of a port is the connection for a printer.
   Controllers can be USB ports that allow you to
   attach input devices, such as a joystick for gaming.
5. Input devices are used to allow you to communicate
   with the computer. These will be keyboard and mouse,
   and even something as exotic as a tablet, used in photo
   refinishing and 3D and graphic work.
6. Secondary storage units store your data. Long gone
   are the days of a 512 MB hard drive - today you can get
   sizes up to 500 gigabytes and even higher. These units
   store your operating system, programs such as word
   processors, and the system that allows you to connect
   to the internet. Floppy drives are no longer in vogue,
   but if your computer has a floppy drive, it is used
   to access a 3 1/2" floppy for data storage. These days
   people usually use CD-ROM and DVD optical drives for
   secondary storage, allowing for greater capacity
   storage. There are also external back up drives
   available for the computer that allows you to back up
   important data. Available today is a one terabyte
   external drive which holds more information than
   anyone could ever use. Also available are flash drives,
   also known as jump drives and pen drives. These small
   devices make it very convenient to transport data in
   a very small package, and can hold a large amount of
   data.
7. Buses are a collection of wires that connects
   various parts of your computer. Think of a bus as a
   highway on which data travels. Buses consist of two
   types - an address bus and a data bus. The data bus
   transfers actual data whereas the address bus transfers
   information about where the data should go.
8. The operating system is what allows you to interact
   with the computer. The three main operating systems
   available today are Windows, Macintosh OS, and Linux
   in various forms. Windows is probably the most popular
   OS today, but Macintosh has a strong following. The
   Linux operating system is an open source system that
   has been developed by programmers around the world.
   The Linux OS comes in many flavors, and is noted for
   being bullet proof. It is not often seen on s typical
   computer because so many programs are not compatible
   with it. Some people run Linux and Windows in a dual
   boot environment, meaning that they can switch from
   one to the other on start up.

Although computers may seem overwhelming to the first time user, they are built today to be very user friendly, and the programs available will allow you to do just about anything you could imagine. Remember, you can't really hurt a computer. Outside of hardware failures, they are very forgiving.

Alden Smith is an award winning author and regular contributor to DoItYourself.com. He writes on a variety of subjects, and excels in research.