What is an Input Device for a Computer? - Definition & Examples

Input Device Defined

An input device for a computer allows you to enter information. The most fundamental pieces of information are keystrokes on a keyboard and clicks with a mouse. These two input devices are essential for you to interact with your computer. Many other input devices exist for entering other types of information, such as images, audio and video. Input devices represent one type of computer peripheral - the other two types are output devices and storage devices.

Examples of Input Devices

A keyboard is the most fundamental input device for any computer system. In the early days of computing, it was typically the only input device. A keyboard contains keys for letters and numbers as well as for specialized tasks, such as Enter, Delete, etc.

Typical keyboard for a desktop computer

When operating systems started to use graphical user interface (GUI), the mouse was developed as a pointing device. Typically, a mouse resides on a flat surface, and by moving the mouse, you can move the pointer on the screen. One or more buttons on the mouse allow you to enter instructions by clicking. Most models also include a wheel for scrolling.

Typical mouse for a desktop computer

Desktop computers have a separate keyboard and mouse, but for laptops, these are integrated into a computer system itself. In laptops, the mouse is actually substituted with a touchpad or trackpad. This is a specialized surface that follows the motion of your finger. You can still connect an external mouse to a laptop if you prefer.

Keyboard and trackpad on a laptop computer

Another common input device is an image scanner. A typical desktop or flatbed scanner is a device that optically scans printed images and paper documents and converts them into digital images. In most scanners, you place the document on a glass plate and place an opaque cover over it. A bright light moves across the image, and the reflection is captured by a sensor, which converts the document to a digital image.

Flatbed scanner

Audio and video can be recorded using a microphone and video camera, respectively. Due to the popularity of video conferencing using services like Skype, these are now typically integrated in most laptops and monitor displays for desktops; however, you can also connect an external webcam, which can record both audio and video.

External webcam for video conferencing

If you use your computer to play games, you can use the keyboard and mouse to interact with the game, but this has limitations, especially for fast-action games. Instead, you may want to use a joystick or gamepad. A joystick is a pivoted stick that you can move around with your hand to simulate movement - sort of like what a helicopter pilot uses. A gamepad is a hand-held controller with a series of unique buttons to provide inputs specific for computer-based gaming. A gamepad looks very much like the controllers used for video consoles.

Gamepad with unique buttons for gaming purposes

While keyboards and mice have been around for decades, a more recent development is the use of touch screen technology. A touch screen has become the primary input method for smartphones and tablet computers. Instead of using a mouse, you simply use your finger to click directly on the screen. What if you want to type something? Most touch screen devices have a virtual keyboard that appears on the screen when needed.

Typing on a tablet computer

Lesson Summary

Input devices allow you to interact with your computer. These include devices for text, pointing, gaming, images, audio and video. These devices are becoming increasingly integrated into computer usage. The latest generation of tablet computers has all these input methods built into the tablet itself.

Learning Outcomes

After this lesson is done you should be able to:

• Explain the role of input devices
• Recall and describe a variety of input devices currently available