Computer input devices are accessories that control how a computer processes information. For instance, a mouse is an input device that controls the pointer and helps users interact with the windows on the screen. Input devices are the accessories that give the computer's central processing unit (CPU) data with which to work. The CPU processes the information and then displays results to the user. Without input devices, the computer would just display data without any interaction.
The mouse is a basic input device for the computer. Mice were an enhancement to the keyboard, which is the main input device of a computer. A mouse allows the user to click on a button or interact with the computer without using both hands for typing. It is also an integral part of a Windows machine. Although most Windows forms have alternate key functions, the use of a mouse is more intuitive for end-users.
The joystick is used mainly for playing games. Joysticks were first used in console gaming, such as the Atari and Commodore 64. When computers began to be a part of every home, video games flooded the market. To improve on gamers' experiences, the hardware manufacturers developed joysticks that connected to computers. Joysticks give video games commands, so they are a part of the input device category.
The keyboard is the main input device for computers. For instance, boot up a computer without a keyboard and it stops, warning the user that no keyboard is attached. The keyboard is the only tool available at the command prompt, so it is a necessity for a computer. It is also used in almost every application, including spreadsheets, email, word processing documents and coding.
Scanners are devices that record images from documents or photographs. The scanner runs over the colors and writing on the paper, and the device sends it to the computer. Users normally have custom software that is included with the scanner. This software displays the images that were taken from the scanner's surface.
Two types of cameras are used for input on a computer. The digital camera is a device that takes digital images and saves them to memory. The user then connects the camera to the computer, where images are uploaded and saved. Web cams are the other type of camera that connects to the computer. Web cams are video cameras that enable communication with other users over the Internet.