How Does a Computer Keyboard Work?

A computer keyboard is an input device that issues instructions for the computer to follow. The standard keyboard arrangement includes 80 to 110 keys including alphabetical keys, a numeric keypad, alphanumeric keys, symbols, function, and control keys. Based upon the chosen language and typing preferences there are different keyboard arrangements available, the most common being the QUERTY.

The Mechanics

The keyboard is actually a mini computer with a circuit and switch under each key. When a key is pressed, the switch sends a small current to a processor within the keyboard. After the current is picked up, it sends a signal to the central processor of the computer, which then interprets the command and acts accordingly.

Command Keys

The command keys "Shift," "Ctrl," and "Alt" modify the way in which other keys operate. These keys have different functions depending on the computer manufacturer and designated operating system. While most keyboard strokes produce letters, numbers, or special characters, pressing a combination of keys results in a computer command. For example, using the Control+Alt+Delete combination issues a special command to the operating system of the computer to shut down and reboot.

The Connection

Keyboards for standard desktop computers use a cable with a USB (Universal Serial Bus) connector, while laptops use an internal connector. The cable carries power to the keyboard and relays signals from the keyboard back to the computer.

Wireless keyboards are connected to the computer through radio frequencies (RF) or infrared (IR) connections that are similar to the remote control you use for your television. Bluetooth connections like the one your cell phone headset uses are popular as well. Each connection requires a receiver that is either plugged into a USB port or built into the device to communicate with the computer and must rely on batteries or an AC connection to power up.