The “computer” is an ensemble of different machines that you will be using to get your job done. A computer is primarily made of the Central Processing Unit (usually referred to as the computer), the monitor, the keyboard, and the mouse. Other pieces of hardware, commonly referred to as peripherals, can enhance or improve your experience with the computer.

Author Note

This web site assumes that you have a computer ready to be used and
that all the necessary parts are connected; but we don’t care if you are
using a desktop, a laptop, a server, whether you work from home, in an
office, while commuting, taking a class, or using a computer at a public
library.

To use the computer, you must first turn it on. To do
this, the first thing you should find is the power switch that is used to put the unit on. Nowadays, it is usually located in front of the computer. Pushing it would start the
computer. 

The computer works by receiving and giving
instructions (in future lessons, we will learn that an instruction or a
group of instructions is actually called a program). For example, when you
press the power button, you give the instruction to the electricity to
“wake” up the computer. This instruction causes the computer to
start giving its own instructions to internal parts. One of the
instructions is called BIOS (it stands for Basic Input/Output System). The BIOS instruction starts checking “everybody”,
asking “Are you OK?”, “Are you OK?”, “What about
you?”. If a certain part that is important doesn’t respond (for
example if a certain important object such as the keyboard or mouse is not
connected, which means it will not respond when the BIOS asks, “Are
you OK?”), then the BIOS may interrupt everything, or it may continue
checking. If the BIOS comes to a conclusion that this computer is not
worth using, it would display an error and may not let you do anything
significant. If the BIOS “thinks” that everything is alright and
that the computer can be used, then it gets the hardware parts ready.

Depending on the computer you are using, when it comes
up, it may directly display the desktop or it may ask you to log in.
Because there are so many scenarios, we cannot review all of them. If you
are using Microsoft Windows 95, 98, Millennium, or XP, the desktop may
display once the computer is ready. Some installations of Windows 98 may
first display a logon window to you, you can just click OK and you will
be fine. Again, there are too many scenarios, we cannot review all of
them.

From now on, we will consider that you are able to
start your computer just fine.

Source Article