Input device: A device that inputs data and information to a computer. It is the bridge between the computer and the user or other devices. The input device is one of the main devices for information exchange between the user and the computer system. Keyboard, mouse, camera, scanner, light pen, handwriting pad, joystick, voice input device, etc. are all input devices. An input device (InputDevice) is a device that interacts with a computer by a person or an outside person to input raw data and the programs that process those numbers into the computer. The computer can receive a variety of data, both numerical data, can also be a variety of non-numerical data, such as graphics, images, sound, etc. can be input to the computer through different types of input devices for storage, processing and output. Output Device (Output Device) is the terminal device of the computer hardware system, which is used to receive the output display, printing, sound, and control the operation of peripheral devices. It is also the performance of various calculation results data or information in the form of numbers, characters, images, sounds, etc. Common output devices are monitors, printers, plotters, image output systems, voice output systems, magnetic recording equipment and so on.