The main graphical input devices are scanner and light pen.
Input: Mouse and Keyboard Output: Monitor and printer
Two main input devices are the keyboard and the mouse.
Generally, the two main input devices are a keyboard and mouse, while the two main output devices are a monitor and printer.
mouse & keyboard
There are no inherent disadvantages in having or using an input device. As a matter of fact, there simply aren't any alternatives, so it would be largely irrelevant, anyway.
As there is no alternative to input and output devices, other than doing nothing, they have no inherent disadvantages.
Input Devices provide input signals to Computing devices. There can be disadvantages for a particular type of Input Device such as Mouse, Keyboard, Pointers etc. Nonetheless without Input devices Computer might not be able to receive information & remain useless.
Two main input devices are the keyboard and the mouse.
The mouse, keyboard, microphone, scanner, joystick and webcam.
Neither. A computer contains both input and output devices. Many modern input and output devices contain embedded computers, that interface between the main computer and the actual input or output hardware of the device.
Peripheral devices are typically classified into two main types: input devices and output devices. Input devices, such as keyboards and mice, allow users to enter data into a computer. Output devices, such as monitors and printers, display or produce the results of computer processes. Some devices, like multifunction printers, can serve as both input and output devices.