A computer generally means a programmable machine.
A computer is a device that accepts information and manipulates it for some result based on a program or sequence of instructions on how the data is to be processed.
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INPUT+PROCESS=OUTPUT
INPUT
• Data Sheets
• Labor
• Computer
• Desk
• Chair
• Electricity
PROCESS
• Data Entry
• File Data Sheets
OUTPUT
• Entered Data
• Filed Data Sheets
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Computer
Classification: Computers can be generally classified by size
and power, There are :
· Personal computer: A small, single
user computer based on a microprocessor. In
addition to the microprocessor, a personal
computer has a keyboard for entering data,
a monitor for displaying information, and
a storage device for saving data.
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Workstation: A powerful, single-user computer. A workstation is like a personal computer, but it has a more powerful microprocessor and a higher-quality monitor.
Minicomputer: A multi-user computer capable of supporting from 10 to hundreds of users simultaneously.
Mainframe: A powerful multi-user computer capable of supporting many hundreds or thousands of users simultaneously.
Supercomputer: An extremely fast computer that can perform hundreds of millions of instructions per second.
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Hardware :Consists of devices, like the computer itself, the MONITOR,
KEYBORD, PRINTER, MOUSE and SPEAKERS. Inside the computer there are more bits of
hardware, including the motherboard, where you would find the main processing chips that make up the central processing unit (CPU). The hardware processes the commands it receives
from the software, and performs tasks or calculations.
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The Different Types of PC Monitors:
PC monitors come in two different flavors, each of which is known by a popular TLA (three-letter acronym): LCD and CRT.
*LCD: Stands for liquid crystal display. The newer, flatter type of computer screen.
*CRT: Stands for cathode ray tube. The traditional, glass-screen, television-set-like monitor.
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KEYBORD:A keyboard is the set of typewriter-like keys that enables you to enter data into a computer. Computer keyboards are similar to electric-typewriter keyboards but contain additional keys.
The keys on computer keyboards are often classified as follows:
*Alphanumeric keys Letters and numbers
*Punctuation keys Comma, period, semicolon, and so on.
*Special keysFunction keys, control keys, arrow keys, Caps Lock key, and so on.
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MOUSE:A device that controls the movement of
the cursor or pointer on a display screen.
Different Types:
Ball Mouse
Optical Mouse
Laser Mouse
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PRINTER: A printer is any device that
prints text or illustrations on paper.
There are many different types of printers.
Daisy-wheel
Dot-matrix
Ink-jet
LCD & LED
Line printer
Thermal printer
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SPEAKERS: Speakers are popular output
devices used with computer systems. They
receive audio input from the
computer's sound card and produce
audio output in the form of sound waves.
Different Types of Computer Speakers:2.1 Speaker5.1 Speaker7.1 SpeakerWireless
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SOFTWEAR:
Software means computer instructions or data.Anything that can be stored electronically issoftware, in contrast to storage devices and displaydevices which are called hardware.
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CPU - CENTRAL PROCESSING UNIT
CPU is the abbreviation for central processing unit.
Sometimes referred to simply as the central
processor, but more commonly called processor,
the CPU is the brains of the computer where most
calculations take place. In terms of computing
power, the CPU is the most important element of
a computer system.
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ROM(Read-only memory) :Read-only memory, or ROM, is a form of data storage in computers and other electronic devices that can not be easily altered or reprogrammed. RAM is referred to as volatile memory and is lost when the power is turned off whereas ROM in non-volatile and the contents are retained even after the power is switched off.
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RAM(Random-access-memory): Random-access memory, or RAM, is a form of data storage that can be accessed randomly at any time, in any order and from any physical location in contrast to other storage devices, such as hard drives, where the physical location of the data determines the time taken to retrieve it.
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Media is the material used in devices.
Example : Floppy Disk and CD-ROM
If CD-ROM is the media then CD-ROM drive is
the device.
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OS - operating
system:
The operating system is the most
important program that runs on a computer. Every
general-purpose computer must have an
operating system to run other programs.
Operating systems perform basic tasks, such as
recognizing input from the keyboard,
sending output to the display screen, keeping
track of files and directories on the disk, and
controlling peripheral devices such as disk
drives and printers.
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Computer Network : A computernetwork is a group of computersystems and other computinghardware devices that are linkedtogether through communicationchannels to facilitate communicationand resource-sharing among a widerange of users. Networks arecommonly categorized based on theircharacteristics.4/9/2015
Categories of computer network:There are many types of networks, including:Local Area Networks (LAN)Personal Area Networks (PAN)Home Area Networks (HAN)Wide Area Networks (WAN)Metropolitan Area Networks (MAN)Backbone Networks (BBN)Global Area Networks (GAN)Campus Networks InternetworksThe Internet
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