While typewriters are the definitive ancestor of all key-based text entry devices, the computer keyboard as a device for electromechanical data entry and communication derives largely from the utility of two devices:

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Different types of keyboards are available and each is designed with a focus on specific features that suit particular needs. Today, most full-size

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Chorded
While other keyboards generally associate one action with each key, chorded keyboards associate actions with combinations of key

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Keyboards and keypads may be illuminated from inside, especially on equipment for mobile use. Both keyboards built into computers and external ones may support backlighting; external backlit keyboards may have a wired USB connection, or be

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Key switches
In the first electronic keyboards in the early 1970s, the key switches were individual switches

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Optical character recognition (OCR) is preferable to rekeying for converting existing text that is already written down but not in machine-readable format (for example, a Linotype-composed book from the 1940s). In other words, to convert the text from an image to

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Alphanumeric
Alphabetical, numeric, and punctuation keys are used in the same fashion as a typewriter keyboard to

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