Keyboards are computer input devices that are used to produce letters and numbers while typing. Each individual key on the keyboard has a symbol or letter printed onto it, and these symbols and letters correspond to input signals for whatever program is being used.
The standard keyboard has 101 keys or "key-caps," laid out in a QWERTY configuration.
Keyboards are made from water-cut plastic, which is how the frame of the keyboard with slots for each key is made.
The Key Matrix
Beneath the keyboard lies a circuit board called the key matrix, which consists of lots of tiny circuits. When a key is pressed, a circuit on the key matrix is completed, sending a current / signal to the character map.
The Character Map
The character map is memory contained in the keyboard's microprocessor that contains all the information that corresponds to what key is being pressed. So when the "B" key is pressed, the character map is what determines that a "B" should show up on the screen.
Keyboards use a USB cable to connect the device to the computer, but there are also wireless keyboards available now that take advantage of Bluetooth technology.