Notesale: Turn your study into money

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Information
 Uses of computer
 The components of computer
 Basic characteristics of a computer
 Advantages of using computers
 Disadvantages of using computers
 Classification of computers
 Impact of computers on society

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What is a computer?
A computer is an electronic device, operating under the control of instructions stored in
its own memory, that can accept data, process the data according to specified rules,
produce results, and store the results for future use
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Those functions are:


Input—typing characters at a keyboard, moving the mouse around the screen or
speaking to a computer



Output—displaying characters or pictures on the screen, printing a research paper,
or sending an e-mail message



Process—calculating the square root of a number, sorting a list of names, or
producing a three-dimensional image



Store—saving your research paper or resume, keeping track of your credit card
purchases, or archiving digital pictures of your relatives



Retrieve—recalling a list of addresses or business contacts
Computers perform these five fundamental functions in different ways and at
different speeds, but they all use digital data to perform the tasks
...
Data is a collection of unprocessed items,
which can include text, numbers, images, audio, and video
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Information Processing Cycle
Computers process data (input) into information (output)
...
A collection of related instructions organized for a common purpose is referred to as
software
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Some people refer to the series of input, process, output, and storage activities as the
information processing cycle
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As a result, communications also has become an essential element of the
information processing cycle
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College students spend an average of 5-6 hours a week on the internet
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Students exposed to the internet say they think the web has helped them improve the
quality of their academic research and of their written work
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This offers a variety of internet and video-based online
courses
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All medical information can now be digitized
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Mental health researchers are
using computers to screen troubled teenagers in need of psychotherapy
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Science:
Scientists have long been users of it
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An example is space physics where space physicists
are allowed to band together to measure the earth’s ionosphere
from instruments on four parts of the world
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Some areas of business that are undergoing
rapid changes are sales and marketing, retailing, banking, stock
trading, etc
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The internet has
become a popular marketing tool
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Recreation and Entertainment:
Our entertainment and pleasure-time have also been affected by
computerization
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o

In sports, computers compile statistics, sell tickets, create training programs and
diets for athletes, and suggest game plan strategies based on the competitor’s past
performance
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Government:
Various departments of the Government use computer for their planning, control and law
enforcement activities
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Defense:
There are many uses computers in Defense such as:


Controlling UAV or unmanned air-crafts an example is
Predator
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The show future weapon gives an entire hour to the predator
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

Computers are used to track incoming missiles and help slew weapons systems onto
the incoming target to destroy them
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

Computers are used in the logistic and ordering functions of getting equipment’s to
and around the battlefield
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

Computers help design and test new systems
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Input Devices
An input device is any hardware component that allows you to enter data and instructions
into a computer
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A computer keyboard contains keys you press to enter data into the computer
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A mouse is a small handheld device
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A
microphone allows you to speak into the computer
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A Web cam is a digital video
camera that allows you to create movies or take pictures and store them on the computer
instead of on tape or film
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Three commonly used output devices are a printer, a monitor, and speakers
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A monitor
displays text, graphics, and videos on a screen
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System Unit
The system unit is a case that contains the electronic components of the computer that
are used to process data
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Two main components on the motherboard are the processor and memory
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Memory
consists of electronic components that store instructions waiting to be executed and data
needed by those instructions
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Common computer hardware components include a keyboard, mouse, microphone, scanner, Web cam,
printer, monitor, speakers, system unit, hard disk drive, external hard disk, optical disc drive(s), USB flash
drive, card reader/writer, memory cards, and modem
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For example, computers
can store hundreds or millions of customer names and addresses
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A computer keeps data, instructions, and information on storage media
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A storage
device records (writes) and/or retrieves (reads) items to and from storage media
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For example, a DVD drive (storage device) accepts DVD (storage media)
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A USB flash drive is a portable storage device that is small and lightweight
enough to be transported on a keychain or in a pocket
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You plug a USB flash drive in a special, easily accessible
opening on the computer
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The average
hard disk can hold more than 320 billion characters
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Although some are portable, most are housed inside the system unit
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An external hard disk is a separate,
freestanding unit, whereas you insert and remove a removable hard disk from the
computer or a device connected to the computer
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CDs, DVDs, and
Blu-ray Discs are three types of optical discs
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Some DVDs can store two full-length movies or 17 billion characters
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Some mobile
devices, such as digital cameras, use memory cards as the storage media
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Communications Devices
A communications device is a hardware component that enables a computer to send
(transmit) and receive data, instructions, and information to and from one or more
computers or mobile devices
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Communications occur over cables, telephone lines, cellular radio networks, satellites,
and other transmission media
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Basic characteristics of a computer


Speed: As you know computer can work very fast
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You will be surprised to know that computer
can perform millions (1,000,000) of instructions and even more per second
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From this you can imagine how fast
your computer performs work
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The accuracy level is 7 determined on the basis of
design of computer
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

Diligence: A computer is free from tiredness, lack of concentration, fatigue, etc
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If millions of calculations are to be performed,
a computer will perform every calculation with the same accuracy
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

Versatility: It means the capacity to perform completely different type of work
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Next moment you may use it for inventory
management or to prepare electric bills
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Any information can be stored and recalled as long as you require
it, for any numbers of years
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

Storage: The Computer has an in-built memory where it can store a large amount of
data
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Advantages of using computers
Benefits from using computers are possible because computers have the advantages of
speed, reliability, consistency, storage, and communications
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Many computers process billions or
trillions of operations in a single second
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Consistency: Given the same input and processes, a computer will produce the same
results — consistently
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Many computers store enormous amounts of data and
make this data available for processing anytime it is needed
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Computers with this capability can share any of the four information
processing cycle operations — input, process, output, and storage — with another
computer or a user
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

Violation of Privacy: Nearly every life event is stored in a computer somewhere in medical
records, credit reports, tax records, etc
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

Impact on Labor Force: Although computers have improved productivity in many ways
and created an entire industry with hundreds of thousands of new jobs, the skills of
millions of employees have been replaced by computers
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A separate impact on the labor force is that some
companies are outsourcing jobs to foreign countries instead of keeping their homeland
labor force employed
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Some of
these unsuspecting, innocent computer users have fallen victim to crimes committed by
dangerous strangers
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For example, do not share information that
would allow others to identify or locate you and do not disclose identification numbers,
passwords, or other personal security details
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They are
classified according to purpose,
data handling and functionality
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General purpose
computers are designed to perform
a range of tasks
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Specific purpose computers are designed to handle a specific problem or to perform a
specific task
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According to data handling, computers are analog, digital or hybrid
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Modern analog computers usually employ electrical parameters, such as
voltages, resistances or currents, to represent the quantities being manipulated
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They measure continuous physical
magnitudes
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Such computers process data into a digital value
(in 0s and 1s)
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Hybrid
computers incorporate the measuring feature of an analog computer and counting feature
of a digital computer
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According to functionality, computers are classified as:
Analog Computer
An analog computer (spelt analogue in British English) is a form of computer that
uses continuous physical phenomena such as electrical, mechanical, or hydraulic
quantities to model the problem being solved
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Hybrid Computer (Analog + Digital)
A combination of computers those are capable of inputting and outputting in both digital
and analog signals
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On the basis of Size
Super Computer
The fastest and most powerful type of computer
Supercomputers are very expensive and are employed
for specialized applications that require immense
amounts of mathematical calculations
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Other
uses of supercomputers include animated graphics,
fluid dynamic calculations, nuclear energy research,
and petroleum exploration
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Mainframe Computer
A very large and expensive computer capable of
supporting hundreds, or even thousands, of users
simultaneously
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In some
ways, mainframes are more powerful than
supercomputers because they support more
simultaneous programs
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Mini Computer
A midsized computer
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In the past decade, the distinction between large minicomputers and small
mainframes has blurred, however, as has the distinction between small minicomputers
and workstations
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Micro Computer or Personal Computer
•

Desktop Computer: a personal or micro-mini computer sufficient to
fit on a desk
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It is generally smaller in size than a desktop
computer and larger than a notebook computer
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Palmtops have no keyboard but the screen serves both
as an input and output device
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In this context, workstation is just a generic
term for a user's machine (client machine) in contrast to a "server" or "mainframe

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