The Definition of Input Devices
Input devices are hardware components that enable users to interact with a computer. Without input devices, you would not be able to feed instructions to a computer. The most common input devices in modern computers are the mouse (or pointing device), the keyboard, the scanner, the webcam and the microphone. Another input device, serving a niche purpose, is the joystick, used in gaming.
Role Of Input & Output
An input device instructs the computer to execute a task. The computer's processor works on the task at hand, and provides feedback after the instructions have been carried out.
Modern keyboards have alphanumeric keys and other buttons for special functions. A typical keyboard has more than 100 keys, including the number pad, function keys F1 through F12 and operation buttons like the keys marked CTRL, TAB, ALT and DEL. The most popular layout, the QWERTY is not a universal standard; other keyboard layouts may be used for special purposes.
The mouse, one of the most popular input devices, lets a computer user navigate on-screen without having to learn hundreds of keyboard shortcuts. The mouse is critical, especially in the graphical user interface (GUI) environment of modern operating systems in which all software programs are designed for its use. In laptop computers, another pointing device---a flat panel that translates finger motion to cursor movements on screen---replaces the mouse. Laptops also support traditional mice, which can be attached via USB.
The scanner makes digital copies of printed images and text. Flatbed scanners, the most popular, turn printed hard copy, placed on a flat glass panel, into a digital image. Proprietary software enables users to modify and work on scanned images before saving it to disk. Scanners may be integrated with devices like printers and fax machines.
Microphone, Webcam & Joystick
The microphone, webcam and joystick are widely used in the internet environment. Microphones, usually coupled with headphones, can record audio and save it as a digital file. Content recorded with microphones and webcams can be instantly modified with software, and uploaded to the Internet. The joystick is another input device used mainly for gaming, either online or offline. Joysticks are rarely used in general computing.