INPUT AND OUTPUT

Input is any data and instructions enter into the memory of a computer.An input device is any hardware component that allows user to enter data and instructions into a computer,The example of input device are keyboard,mouse,MICR,RFID reader,scanner,microphone and digital camera.The mouse is a pointing device because it allow us to control a pointer on a screen.A keyboard contents keys user press to enter data and instructions into a computer.A trackball is a stationary pointing device with a ball on its top or side.A touchpad is a small,flat and rectangular pointing device that is sensitive to pressure and motions.A pointing stick is a pressure-sensitive pointing device shaped like a pencil eraser that is position between keys on a keyboard.A light pen is a handheld input device that can detect the presence of light.A touch is a touch-sensitive display device.Video game and computer game use a game controller as the input device that direct movement and actions of on-screen objects.Game controller include gamepads,joystick and wheels like guns,dance pads and a variety of motion-sensing controller.Portable media players use a touch-sensitive pad as their input device.Other than that,user have the variety of other options available to enter data and instructions into a computer.These include voice input,input for PDAs,smart phones and Table PCs,digital cameras,video input,scanners and reading devices,terminals and biometric input.
In other hand,output is a data that has been processed into a useful form.An output device is any hardware component that conveys information to one or more people.Commonly used output devices,printers,speakers,headphones,and earphones,fax machines and fax modems,multifunction peripherals and data projectors.A display device visually conveys text,graphics and video informations.a monitor is a display device that is packaged as a separate peripheral.An LCD monitor is a desktop monitor that use a liquid crystal display to produce images.A plasma monitor is a display device that uses gas plasma technology,which sandwiches a layer of gas between two glass plates.In addition to monitors and printers,other output devices are available for specific uses and applications.These include speakers,headphones and earphones,for machines and fax modems,multifunction peripherals and projectors.

COMPUTER PERSPECTIVE

For me,computers are very importants for billions of people.Through computer,people can access to information from around the world.A computer is an electronic device,operating under the control of instruction stored in its own memory.People also spend hour of leisure time using a computer.The benefits of computer are possible because computer have the advantage of speed,realibility,consistency,storage and communications.Many people believe that computer literacy is vital to succes and society can get many benefits from using computers.