Sie sind auf Seite 1von 9

What is Computer?

Computer is the term that was originally given to person who performed numerical
calculations using mechanical calculators such as the slide rule and abacus. Nowadays
a computer is considered to be an electronic device that allows inputting data and
having it stored, processed, or otherwise manipulated quickly and efficiently.
Computers help make jobs that used to be complicated much simpler. For example, a
user can easily write letters in a word processor and edit any portion of the letter
anytime, spell check the letter, and move text from another document into the letter,
etc. his is just one of the hundreds of different things a computer is capable of doing.
he first computer was called the !N"#C, which was built during $orld $ar "".
Computers first utili%ed vacuum tubes and were very large &sometimes room si%e' and
only found in businesses, (niversities, or governments. )ater, computers began
utili%ing transistors as well as smaller and cheaper parts that allowed the common
person to own their own computer.
Basic Computer Concepts
i) Computer Architecture
"t is the overall design and setup of the computer. his includes where each of the
connections and parts of the computer are to be placed, how each of components
operate with each other, dimensions, etc.
oday, most computers are often comprised with some or all of the below
Case or Chassis
C+,-./, C+,-, and0or C+,-$
Floppy disk drive
3ard disk drive
/onitor, )C+, or other display
5ound card
2ideo card
Input devices
#n input device is a hardware device that sends information into the C1(. $ithout
any input devices a computer would simply be a display device and not allow users to
interact with it, much like a 2. 5ome of the computer input devices are as follows
Digital camera
+igital camera is a type of camera that
records and stores pictures or videos. he
main feature of digital camera is the
ability to take do%ens, sometimes
hundreds of different pictures.
Sadiq Merchant; Hamdard University; HIESS; B.Ed-Weekend (2007-200!; Semester" #$%
Basic Computer Concepts
7oystick is an input which allows an
individual to easily navigate an object in
a game such as navigating a plane in a
flight simulator.
.ne of the main input devices used on a
computer, a 1C8s keyboard looks very
similar to the keyboards of electric
typewriters, with some additional keys.
"t is the hardware device that allows
computer users to input audio into their
"t is an input device that allows an
individual to have the ability to perform
various functions on computer such as
opening a program or file.
"t is a hardware input device that allows a
user to take an image and0or text and
convert it into a digital file, allowing the
computer to read and0or display the
scanned object.
Basic Computer Concepts
Web cam
"t is a camera which is connected to a
computer to allow a person to view other
people, places, and even events.
C!" and torage Devices
C1(: also known as a processor or microprocessor: is short for Central 1rocessing
(nit. "t is responsible for handling all instructions and calculation it receives from
other hardware components in the computer and software programs running on the
he first C1( was manufactured by
"N!) in ;<=>. he adjacent picture is
on of the latest processors.
"t is a circuit that is the foundation of a
computer and allows the C1(, -#/, and
all other computer hardware components
to function with each other.
"t is a device that enables a computer to
transmit and receive information over
telephone lines.
Basic Computer Concepts
# storage device is a hardware device designed to store information. here are two
types of storage devices used in computers: a 8primary storage8 device and a
8secondary storage8 device. # primary storage device is the storage location that holds
memory for short periods of times. For example, computer -#/, etc. # secondary
storage device is the medium that holds information until it is deleted or overwritten.
For example, hard disks drive, etc. 3ere are few examples of storage devices?
"t is short for -andom #ccess /emory
which is the main memory of the system
within a computer. -#/ requires power:
if power is lost, all data is also lost.
"t can record data as magneti%ed spots on
tracks on its surface. +iskettes became
popular along with the personal computer
mainly to transport data.
$ard Drive
"t is a rigid circular disk located inside a
computer. he term hard disk is often
used as an abbreviation to hard disk
#emovable hard drive
"t is a hard drive that can be placed within
a plastic or metal cartridge that enables it
to be removed easily and placed into
other computers with similar bays.
%ip drive
"t is a data storage device similar to the
5tandard ;.>>@ floppy drive having
capability to hold upto ;AA /* or 6BA
/* of data. *ecause they were cheap,
they became very popular in late ;<<As.
Basic Computer Concepts
CD&#' CD&#W
C+,- is short for C+,-ecordable and is
a type of writable disc capable of having
information written on it only once
C+,-0$ is a drive and0or media that is
capable of being written many times.
(utput Devices
hese devices display and generate information that has been held or generated within
a computer. 5ome examples are shown below.
"t is a video display screen and the hard
shell that holds it. "t is used to visually
interface with the computer and are
similar in appearance to a television.
"t is an external hardware device
responsible for generating a hard copy of
data. "t is commonly used to print text,
images, photos, etc.
"t is a hardware device connected to a
computer8s sound card that outputs
sounds generated by the card.
"t is a device that enables an image, such
as a computer screen, to be projected onto
a flat surface. hese devices are
commonly used for presentations.
Basic Computer Concepts
"t is a device that draws pictures on paper
based on commands from a computer
using a pen. /ulticolor plotters use
different,colored pens to draw different
ii) Introduction to Computer o*t+are and $ard+are
5oftwares are the computer programs containing instructions that cause the computer
to do work. 5oftware consists of a set of instructions a computer uses to manipulate
data, such as a word,processing program or a video game. 5oftware also governs how
the hardware is utili%ed: for example, how information is retrieved from a storage
5oftware as a whole can be divided into a number of categories based on the types of
work done by programs. he two primary software categories are as follows?
". .perating systems &system software' control the working of the computer.
hese softwares handle essential, but often invisible, chores as maintaining
disk files and managing the screen, etc.
"". #pplication software addresses the multitude of tasks for which people use
computers. #pplication software performs tasks like word processing,
database management, and the like.
wo additional categories that are neither system nor application software, although
they contain elements of both, are as follows:
""". Network softwares enable groups of computers to communicate, etc
"2. )anguage softwares provide programmers with the tools they need to write
"n addition to the above task,based categories, several types of software are described
based on their method of distribution. hese include the Following
2. 1ackaged software: developed and sold primarily through retail outlets
2". Freeware and public,domain software: made available without cost by its
2"". 5hareware: usually carries a small fee for those who like the program
Basic Computer Concepts
3ardware consists of the components that can be physically handled. he functions of
these components can be typically divided into three main categories? input, output,
and storage. Components in these categories connect to microprocessors, specifically,
the computerDs central processing unit &C1(', the electronic circuitry that provides the
computational ability and control of the computer, via wires or circuitry called a bus.
hree kinds of hardware are explained as follows?
". "nput 3ardware consists of external devices: components outside of the
computerDs C1( providing information and instructions to the computer.
hese include light pen, mouse joystick, keyboard, ouch,screen displays,
optical scanner, microphone, modem, network interface card, etc.
"". .utput 3ardware consists of internal and external devices that transfer
information from the computerDs C1( to the computer user. hese include
+isplay units likes a video screen with a cathode,ray tube &C-' or a video
screen with a liquid crystal display &)C+', 1rinters, speakers or headphones,
projectors, etc.
5torage 3ardware provides permanent storage of information and programs for
retrieval by the computer. he two main types of storage devices are disk drives and
memory. here are several types of disk drives? hard, floppy, magneto,optical,
magnetic tape, Compact disc drives &C+,-./, C+,-, C+,-$, +2+s, +2+,-, and
+2+,-$', etc.
-ypes o* Computer
Computers are mainly categori%ed into the following types?
Digital Computer Analog computer $ybrid Computer
Digital Computer,
"t is the type of computer that stores data in terms of digits &numbers' and proceeds in
discrete steps from one state to the next. "n digital computers, letters, words and
whole texts are represented digitally. "t performs calculations and logical operations
with quantities represented as digits, usually in the binary number system. +igital
computers can be built to take the solution of equations to almost unlimited precision,
Basic Computer Concepts
but quite slowly compared to analog computers. For many real,time operations, the
speed of such digital calculations is too slow to be of much use.
Analog Computer,
"t is the type of computer that represents data in terms of physical measures or
quantities and proceeds along a continuum constituted by its components. #nalog
computers are especially suited for the solution of complex non,linear equations and
for the simulation of multi,dimensional, parallel and continuous processes. here is
no restriction on the physical processes analog computers may utili%e. "n general,
analog computers are extraordinarily fast, since they can solve most complex
equations at the rate at which a signal traverses the circuit, which is generally an
appreciable fraction of the speed of light. .n the other hand, the precision of analog
computers is not good: they are limited to three, or at most, four digits of precision.
Compared with digital computers, the programming of analog computers is time
consuming and limited in scope.
$ybrid Computer,
3ybrid computers are computers that comprise features of analog computers and
digital computers. he digital component normally serves as the controller and
of differential equations. 3ybrid computers can be used to obtain a very good but
relatively imprecise value, using an analog computer front,end, which is then fed into
a digital computer process to achieve the final desired degree of precision.