In computing, a keyboard is an input device, partially modeled after the typewriter keyboard, which uses an arrangement of buttons or keys, which act as mechanical levers or electronic switches. A keyboard typically has characters engraved or printed on the keys and each press of a key typically corresponds to a single written symbol. However, to produce some symbols requires pressing and holding several keys simultaneously or in sequence. While most keyboard keys produce letters, numbers or signs (characters), other keys or simultaneous key presses can produce actions or computer commands. In normal usage, the keyboard is used to type text and numbers into a word processor, text editor or other program. In a modern computer, the interpretation of keypresses is generally left to the software. A computer keyboard distinguishes each physical key from every other and reports all keypresses to the controlling software. Keyboards are also used for computer gaming, either with regular keyboards or by using keyboards with special gaming features, which can expedite frequently used keystroke combinations. A keyboard is also used to give commands to the operating system of a computer, such as Windows' Control-Alt-Delete combination, which brings up a task window or shuts down the machine.
The keyboard alphabetic, numeric and punctuation keys work like electrical switches which are operated by the user when he hits any key he wants. This is then detected by the matrix circuit which then scans the column where the key has been pressed and sends the information that this key has been pressed. This then proceeds to the PS2 port at the back of the computer, where it remains as electronic data until it is processed by the processor and becomes information that the rest of the system can understand and process. There are two different types of keyboard such as QWERTY and ZWERTY. They are called this because of the way the keyboard keys are laid out. Some keyboard keys have printed characters on them or have engraved characters. Inside of the keyboard is a large bundle of wires which are connected together by something called the matrix circuits and the circuit is open when a button is pressed. This is detected by a scanning signal which is emitted by the chip. The chip inside the computer receives the signal bits and decodes them into the appropriate key pressed. Then the signal is received and sent out down the lead to the connection at the back of the computer and then run into the ram which then sends it to the open program on which the user is using. This is all done within a few milliseconds.
