BY- UPENDRA SHARMA

 It is a electronic machine.  When we gives input in a computer it takes and process then and after then it gives output.  It is a very versatile machine.  It has more much speed 

 There is two type of computer.  1-Analog  2- Digital

 Analog computer are those computer whose handle or process about physical nature.  Ex- temperature, pressure etc.

 Digital computers are binary based computers.  It is create information only two state, namely 0 and 1.

 Micro computer  Mini computer  Main frame computer  Super computer

 Speed  Accuracy  Diligence  Multi tasking  Memory (power of remaining)

 All input output and secondary storage devises of a computer is called peripheral devices.  Input devises  Output devices  Secondary storage devises

 (a) key board  (b) mouse  (c) scanner  (d) joystick  (e) light pen  (f) web cam  (g) mice

It is similar to a type writer. It is use to feed data in a computer. It contain alphabets, digits, special character keys, function keys, and some control keys.  we can use one and more keys together for a special task.  Like ctrl + s to save.  ctrl+ alt+ del to task manager and log off the pc.

 It is a pointing input device.  It is use to move the cursor on the screen.  The muse also use to draw sketches, diagram est..  One type of mouse rolling ball and the second type use optical technique.

 If we want insert image in a computer then we use scanner,  It convert hard copy in soft copy.  A scanner is a optical device that analysis image, text,or hand writing, and convert in to a digital form.

 A joystick is also a pointing device.  It is use to move curser on the screen.  its function similar to a mouse.  It is mainly use to play video games.

 Web cam is input device.  It is use to insert picture in a computer.  By the web cam we can do video calls. And share the live video.

 It is a input devise  It is use to input signature and any hand writing in a computer.

`MICE  IT I s a audio input device.  Which is use to input audio in a computer.  By the mice we can call through the internet in a computer.

 Output devise are those devise of computer that supply information result in the hard copy and soft copy.

 Monitor  Printer  Plotter  Projector  Speech synthesizer

 It is also called visual display unit (VDU).  It is similar like a television.  Whatever we type by the keyboard we can see on monitor  Its comes in two types black white and color.  Black and white shows only two colors, and color monitor display many colors.

 It has three type  (1) CRT (cathode rays tube)  (2) LCD (liquid crystal display)  (3) TFT (thin film transistors)

 A CRT monitor is very similar to a television.  In a cart monitor we show the picture through a picture tube.  The picture tube fire a narrow beam of electronic at the screen, the beam strike the screen and then we show picture.

 LCD monitors is the flat panel monitors.  It has very large numbers of liquid crystal show a picture and text.

 Printers are output devices that refers hard copy output.  It use ink to print in a page.  Printer gives best quality output.  It can print color and black and white.

 There is three types of printers.  (1) Dot matrices printer(DMP)  (2) Ink jet printers  (3) Lager printers

 Dot matrix printer use head ribbon and pins to give output.  Its printing similar to type writer printing.  When we give the print it is reduce very much noise.-  It is slower then inkjets and lager printers.  It is use a tractor feed mechanism to transfer paper through a printer.  It is comes in two size. 80 column dot matrix and 132 Colum dot matrix.

 That printer refers in non impact printer.  Ink jet printers use to color cartridge to printing.  Inkjet printer spray ink into paper to form image or text.  It can print both type color and black.  It reduce might sound it time to print.  in this printer print head moves across the paper horizontally.  print quality measured in DPI, its printing is 150 to 1200 DPI.

 That printer only soles in business.  This printer use a laser beam to produce image or text in a paper.  The main component of this printer is drum and toner  A laser printer can also print in both type color and black and white.  It can print with a speed 4-16 pages per min.  Its printing quality is dpi.

 A plotter is a specialize graphical printing.  It is operated moving a pen.  It is use mechanical or thermal technology to create large amount of image.  It is use to technical drawing or CAD application and graphical image.

 Speaker are use to produce audio output.  That is work in conjunction with sound card to produce the audio output.  Some of the common feature that are included in most of speaker are  An LED indicator.  3.5mm headphone jack.  Volume controller  A remote volume control.

 Projector is out put device to use connect to a PC.  It is use to project information on a large screen.  Its widely use to giving permutation.  Any audio video image and text displayed by the projector.  Projector makes presentation more lively and interesting.