A keyboard is an input device that uses a set of finger-sized buttons called keys to enter or manipulate data on a computer or other device. Similar to a typewriter, the keys on a keyboard act as switches or levers but can also be combined to perform complex operations. Some keyboards are built into a device, as in the case of laptops, but many keyboards are peripheral devices that are either wired through a USB cable or connected wirelessly via Bluetooth.
Types of keys
Although the total number of keys on a keyboard varies from manufacturer to manufacturer, they can be grouped into five distinct categories:
- Alphanumeric keys, which include letters, numbers, punctuation, and mathematical symbols and are used for nearly all computer operations
- Numeric keys, which are primarily used for data entry (not all keyboards have a numeric keypad)
- Cursor keys, which are used for navigation
- Control keys, which are used to modify other keys, perform simple actions like delete, or make all letters capitalized
- Function keys, which are programmed to perform more complex actions depending on the operating system and active application
The number of keys in each group and their arrangement has evolved over time. The original AT keyboards developed for PCs had 84 keys, including Control, Return, Shift, Page Up, Page Down, Home, End, Insert, Num Lock, and Caps Lock. In the 1980s, IBM introduced an enhanced keyboard that included function keys meant for quick actions like boot processing and text commands. Enhanced keyboards have since come to represent the majority of default keyboards shipped with PCs today. A number of manufacturers have developed keyboards that also include controls for display brightness, pausing or rewinding audio, and speaker volume among other features.
Types of keyboards
Each keyboard manufacturer offers some type of unique design variation to attract customers, but the order of alphanumeric keys will usually follow the QWERTY standard or one of its adaptations.
Named for the letter keys in the upper left corner of the set, the QWERTY keyboard was designed in the 1800s for mechanical typewriters. It was rumored that the arrangement of keys was intended to prevent the key mechanisms from jamming, but researchers have not been able to verify this claim. Although the QWERTY standard was designed using the Latin alphabet, it has been adapted to accommodate many writing systems including Arabic, Japanese, and Chinese.
The French AZERTY keyboard and German QWERTZ keyboard are very similar to the QWERTY keyboard, except with specific keys swapped for others. Other adaptations include the Dvorak keyboard, which was developed to enhance typing speed; the Maltron keyboard, which features completely separate sets of keys for the right and left hands; and the Colemak keyboard, which has a rearranged set of letter keys and a second backspace key instead of a Caps Lock key.
As new technologies emerge, new keyboards are also frequently introduced to create a better user experience. These include:
- Capacitive: Uses changes in capacitance to register when a user has depressed a key.
- Chiclet: Features elevated keys that have some space between them in a design that is rectangular in shape with rounded edges.
- Gaming: Features additional programmable keys, macro functions or digital displays for use in computer games. They are usually backlit and are more robust with mechanical switches and laser-etched keys for durability.
- KALQ: A style of gesture-based, on-screen keyboard that’s optimized for rapid, two-thumb typing on Android devices. (KALQ is still in beta version.)
- Membrane: The keys are covered by a transparent, plastic shell. Often found in medical facilities.
- Multimedia: A computer keyboard that contains additional keys and buttons for media options such as volume, brightness and video controls.
- On-Screen: An application that provides a visual keyboard on your display screen that can be used in place of a physical keyboard.
- Virtual: A full-size image of a QWERTY keyboard that is projected onto any surface.
- Vertical: A three-dimensional keyboard designed for ergonomic benefits that raises the wrists to a more neutral position and promotes better posture.
- Wedge: Hardware or software that interfaces with a computer to translate data read by a device other than a keyboard, such as a magnetic strip or bar code reader.
Keyboards have become a critical factor in a user’s efficiency and productivity. As such, many operating systems and applications have developed keyboard shortcuts that enable a user to perform actions they would otherwise need to use a mouse to do. Examples of keyboard commands using the Control key (or Command key on Macs) include:
- Control+A: Selects all data within a given view
- Control+B: Changes the selected text to be bold font
- Control+C: Copies selection
- Control+D: Bookmarks the current page in most browsers
- Control+F: Opens a search box for the current browser or application window
- Control+I: Changes the selected text to be italicized font
- Control+P: Opens a print dialogue box for the current window
- Control+V: Pastes the copied selection
- Control+X: Cuts selection
- Control+Z: Undoes the most recent action