Lesson About Computer Components for Competitive Exams
generally computers are used to process the data and to store the data .to do these jobs
There are Three types of Components
these devices are used to send input to computer.this input could be in several formats like text,audio,video etc.,
to give different types of input we use different types of devices for inputting purpose.
Keyboard is used to input text and numeric data.the keyboard layout is same as type writer keyboard.it consists of different sets of keys.
a)Numerical keys/Num pad :- This is to send numeric data
b)Letter keys :- these are used to give Text data.these keys are available from A – Z.
c)Functional keys:-in a keyboard there are 12 functional keys.these keys are used for special purpose.
d)Control keys :- these keys are used to control the movements of cursor on the screen.these keys are upward arrow,downward arrow,left side arrow,right side arrow.Page up,Page down,End,home etc.,
e)Special keys:-Enter,Caps lock,Tab are special purpose keys.these are used for Special purpose.
Mouse is a pointing device.it is used move cursor on the screen.it consists of a round ball at the bottom.it sends signal to the CPU.it is small in size.it consists of one or more buttons.this is very important input device for GUI(Graphical User Interface) operating systems.
It is also a pointing device like Mouse.This device consists of a spherical ball in both upper and lower ends.Joy sticks are often used to control Video games.it is also used in Computer Aided designing.
To transfer information on the paper to the computer this device is used.generally pictures are sent to the computer by using this device.The main purpose of this device is to scan image,printed test,hand written text,an object and convert it in to digital copy.
To send Sound data to computer for storing in digital format this device is used.This device is used in Multimedia applications.
Storage devices are used to store information.there are two types memory units. one is Primary memory and second is Secondary memory.primary memory is temporary memory which will be lost after switching off the computer.RAM(Random Access memory) is the example for Primary memory.secondary memory is permanent memory.Hard disk,floppy disk are best examples for secondary memory.
for storing information/data permanently now a days different types of storage devices are available.
a)Magentic Storage devices like Hard disk,Floppy disk,Zip Disk etc.,
b)Optical storage devices like Blue ray disc,DVD,CD-ROM
c)Flash memory devices like Memory stick ,memory card etc.,
Output device is a computer hardware component that receives information from the computer.
output devices are
this is also referred as VDT (Visual display terminal) and VDU(Visual display tube).earlier computer monitors are fixed with CRT(Cathode ray tube).now a days monitors are made with flat panel display technology.This device displays the information on the screen.
To take a hard copy printers are used.these are externally connected to the computer.these are used to print text,photos.
types of printers.
a)Dot matrix printer:- it prints in the pattern of dots.the quality of the print is measured by DPI(Dots per inch).
These printers are very low in processing and the price is very low.
b)Inkjet printer :-they prints text on the paper by spraying the ink.these devices produces high quality of output.
c)Laser printers:- these devices use laser lights to produce output on the page.
d)Daisywheel printer :-it is invented by David.S.lee.
e)Line printers:- these printers prints each line at a time.
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