Overview of the Computer
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Introduction
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The computer as we know it is a group of
pieces of hardware put together to
get a job done faster. To accomplish its various tasks,
the computer is made of different parts, each serving a particular
purpose in
conjunction with other parts. You don't necessarily need
to know how these parts operate, at least not at this time, but you
should be aware of their co-dependence to take advantage of their
various
characteristics.
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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.
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
From now on, we will consider that you are able to
start
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Practical Learning: Starting a Computer |
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The Central Processing Unit (CPU)
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The most important part, also called the Central Processing Unit or CPU,
is a box that includes many
pieces that are not particularly relevant to us at this time. These
pieces,
inside of the box, perform the jobs of the computer. One of the
assignments of
this unit is to join all the other pieces connected to it. Another job
of this
unit is to perform calculations,
exactly the same types of calculations you were performing in primary
school,
except that this box can handle them very (extremely) fast, so fast that
there
is no human being who can match that speed. Besides the calculations,
this unit also performs other assignments that it receives from various
sources including
you and the external units that are connected to the CPU.
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From now on, the word "user" will refer to anybody who uses or is using a computer. That includes you, or me. |
The Monitor
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The monitor is the video display you will be looking at, most of the
time, to evaluate your work, find out whether the assignments are being
carried out
satisfactorily. A monitor is largely controlled by some pieces of
hardware inside of the computer. But the monitor itself is mainly used
to display your work in a graphical setting you can easily
interpret. To display what is going on with the computer, the monitor is
connected to the computer using a cable. The connection is usually
done
from the back of both machines:
This connection is only a convention or a
convenience, not a rule.
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Monitors come in different sizes. The (most important) size of the monitor is measured diagonally on the screen and is given in
inches:
Based on this, monitors range in sizes of 12",
14", 15", 17", 19",
21", 24', or 29", etc. Monitors are also characterized by the
flatness of their screen. The flatter and the wider screens are usually
the better.
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The Keyboard
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A computer keyboard is a wide object that is equipped
with buttons on which there are letters and numbers:
To distinguish them from other objects, and to
synchronize their names with other objects that use similar settings, such
as the piano, the buttons on the keyboard are called keys.
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From now on, unless specified otherwise, throughout this site, the word "key" refers to the objects you see on the computer keyboard. |
To provide a better management, the keys on a keyboard
are divided in sections. This arrangement is by convention so the users
would be familiar with them and be able to use any keyboard they come in
contact with.
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The Mouse
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A mouse is an object that is meant to fit the
proportions of a hand and is positioned on the table so the user can move
it easily. Like the other parts, a mouse is connected to the computer,
usually to the back, by a cable. Nowadays, it is not unusual to have a
wireless mouse so that it doesn't need a cable.
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The Peripherals
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All the parts we have reviewed so far are usually
required for the computer to function. Some other parts, not required, can
also be connected to the computer to complement it. A peripheral is an
object attached to the computer to help it perform some necessary
assignments none of the other parts can handle. In most scenarios, no
peripheral is required but nowadays, it is unusual for a computer not to
have any peripheral at all. The most used peripherals are the printer, a digital camera,
a scanner, a projector, an
external drive (such as an external CD burner for an old computer or an
external hard drive), etc.
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Types of Computers
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The Desktop
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A computer is referred to as "desktop" when
it is relatively small enough to be
positioned on top of a table where a person is working. Such a computer can also
be placed on the floor or somewhere under, or aside of, the table, in
which case the monitor would be placed on top of the table. This is the
most common type of computers used in the office or at home.
A desktop computer is made of different parts that are
connected with cables.
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The Laptop
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A computer is called laptop when it combines the CPU,
the monitor, the keyboard, and the mouse in one unit to be so small that
you can carry it on your laps when traveling or commuting. A laptop is also
called a notebook. Other parts, such as
an external mouse, an external keyboard, a monitor, or peripherals such as a printer
or a projector, can be connected to the laptop. A laptop is only
physically smaller than a desktop but, everything considered, it can do
anything that a desktop can do.
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The Server
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A server is a computer that holds information that
other computers, called workstations, can retrieve. Such workstations are
connected to the server using various means. This means that they could be
connected using cable, wireless connection, etc. Only computers that
maintain a type of connection with the server can get the information that
is stored in the server.
Normally, although not particularly recommended, any
computer, including a desktop or even a laptop can be used as a server, as
long as it can do the job required. A server is more defined by the
program (called an operating system) that is installed in it, not how the
machine looks.
Any type of computer, including a desktop, a laptop, a
CD or DVD machine, etc can be connected to a server. The person who sets
up a server also defines the types of connections it is made for.
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The Mainframe
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A mainframe is a computer, usually physically big, that
does almost all the jobs for other types of computers that are connected to
it. This is a broad definition but other aspects are involved. Like a
server, the program (operating system) that runs in the mainframe defines
its role.
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Anatomy of the Microsoft Windows Desktop
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Introduction to the Desktop
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After you have started the computer, the area you are
looking at is called the desktop. The desktop is usually different from
one computer to another. This is because some items get added as new
programs are installed on a computer, and other items get deleted at will.
Eventually, you will know how to change the way your desktop looks.
The Microsoft Windows desktop is made of various parts.
From the upper left to the lower left side of the screen, there are small
pictures or images called icons. Each one is used to make the
computer do something. Here is an example:
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The Desktop
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The center and right
empty area you look at is actually the desktop. Whenever you are asked to use the desktop, the request refers to
that whole area.
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From now on, unless specified otherwise, the word "desktop" will always refer to the whole area of the monitor screen. |
The Taskbar
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In the bottom section of the screen, there is (or there may be) a long object.
It is called the Taskbar:
On the left side of the taskbar, there is an object labeled Start
or  .
The appearance of this object depends on the type of Windows you are using but it
plays the same role.
On the right side of Start, there is a wide area that is empty when the computer
starts. This is actually referred to as the taskbar. As you keep using the
computer, this area would be filled with some objects. In some versions (Windows
95, 98, Windows Server 2003), the color of the taskbar may be gray (or Silver).
In some other versions (Windows Millennium), the taskbar may be yellowish. In
Windows XP, it may be blue.
On the far right side of
the taskbar is a section called the tray area. One of the things that this area
displays is the current time (as set on your computer).
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Computer Shut Down
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After using the computer, you can exit from it, which
is also referred to as shutting down the computer. The steps may be different depending on your operating
system.
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