Generally, users need to provide some sort of data or information to a device so as to get desired result. In computer science, input data is provided by the users to the computer system so that it will perform specific task on the data to produce desired output. For an example if a user wants to perform some mathematical computation with the help of computer then some numerical figures and operations to be performed must be given as an input data. After that computer will read out the input data, compute the result and send it back as an output. In other words input can be defined as the amount of investment, efforts or power into a project to retrieve the desired results. Input data can be given to the system in any form such as text, image or an audio. It can be received with the help of input devices like keyboard, mouse, scanner, webcam or microphone. Most of the computer softwares accept input data in the form of stream of bits or the sequence of data instructions that are arranged to perform specific operations.
Multiple input devices are available to send data into the computer directly. These devices usually take an input from the user in specific form (text or sound) and then coverts it into machine readable form for processing. Most frequently used input devices are:
Mouse: It is a pointing device used to move the cursor on the screen to provide specific input to the computer. Generally a mouse works on a flat surface and has three buttons to trigger an action: left button, right button and in center a scroll bar to scroll the things on a computer screen. Laptops have inbuilt touchpad that acts as a mouse. Types of mouses available are: optical mouse, mechanical mouse, trackball mouse and wireless mouse.
Keyboard: keyboard has different keys for characters, symbols, numbers, functions or letters. Input data or instruction can be provided to computer by pressing the specific keys. A keyboard can be attached to a computer by USB port or Bluetooth. QWERTY and AZERTY keyboards are mostly used.
Scanner: It scans images, text documents or printed pages and converts them to the digital file to be displayed on a computer screen as output. Scanner uses an optical technology to transfer pictures or a text image into a computer and then these images can be modified, saved or printed. Flatbet scanner, Drum Scanner, Photo scanner and Sheetfed scanner are some types of scanners available.
Digitizer: Digitizer has a flat screen surface and comes with a pen or stylus. Users can draw images using stylus on the surface of digitizer. These drawn images will appear on the computer screen and can be modified easily. Normally it is used to digitize handwritten signatures on online forms.
Microphone: A device that provides input data in the form of voice signals to a computer. These audio signals are converted to digital format and then can be stored, edited or uploaded. Generally used in chatting, online gaming, teleconferencing and recording audio for music or podcasts.
Webcam: Webcam is a camera attached to a computer or built-in in a laptop. It is used to take photographs or to capture videos and then store them into computer memory. These pictures can be shared later or uploaded onto the internet.
Biometric devices: These devices are used to scan the biological features of a person like fingerprints, face recognition or retina matching for their identification. Frequently used biometric devices are: Fingerprint scanner, Voice scanner, Retina scanner and Face scanner.
Other input devices include: Bar Code Reader, MICR (Magnetic Ink Character Reader), Light Pen, Touch screen, Touch Pad, Joystick, Digital Camera, Paddle, Light gun and many more.