The Definition of Input Devices

An input device by definition is a piece of hardware that enables data to flow into a computer. Common input devices include keyboards, mice and touch screens, which you can use to type or move a cursor, and devices that capture audio and video such as microphones and cameras. Some people use specialized input devices that include scientific and engineering tools like telescopes and microscopes or drawing tools such as styluses and graphics tablets.

Any piece of equipment that's used to send information to a computer can be called an input device. The input devices definition, therefore, includes a wide variety of hardware.

As computers have become ubiquitous, equipment such as scientific tools, musical instruments and TV receivers have been redesigned as computer input devices, and specialized input devices such as keyboards, mice, trackpads and video game controllers have been created expressly to control modern computers.

Among the most familiar types of computer input devices are keyboards, mice and trackpads. These usually come with any modern desktop or laptop computer, and they're integral for typing into a computer and controlling modern operating systems such as Windows and macOS. Some newer computers also ship with touch screens similar to those found on smartphones and tablets. Wireless and Bluetooth keyboards are available for input on devices that ship only with touch screens, such as tablets.

Different devices can have slightly different sets of features, including button layouts and designs. If you're shopping for a keyboard, mouse or something similar for your computer, make sure it's compatible with the software you use and comfortable in your hands.

Many computers now ship with cameras and microphones. These can be used for online chat or for capturing audio, video and photos. You can also attach external audio and video input devices to your computer, including some designed for specific uses such as recording music. Scanners, which capture images of documents, are also common computer input devices. Barcode scanners, such as those found at supermarkets, are available as computer accessories.

You can attach many modern digital musical instruments to computers, where their audio signals are translated into a digital format that you can replay or edit using the computer.

Video game controllers are commonly used with computers by gaming fans. These are similar to the controllers used with standalone console video game systems.

Scientific instruments, ranging from microscopes and telescopes to more obscure sensors, can be used as computer input devices, which makes sense in a world where much scientific research is analyzed on computers and stored on devices such as hard drives.