Keyboard (Computer)

A keyboard is an input device consisting of many keys that, when pressed, send signals to a computer in the form of letters, numbers, punctuation marks, and special commands. It is one of the most commonly used devices through which people interact with computers, typically used alongside a mouse or touchpad.

Its basic design originates from typewriters of the nineteenth and twentieth centuries. When a key is pressed, the keyboard does not send the character directly; it sends a coded signal called a scancode. The operating system and language settings then determine which character is displayed. For this reason, the same key can produce different characters depending on the layout chosen.

Structure of keys

Keys can be divided into several categories. The alphanumeric group consists of letters and numbers. Modifier keys such as Shift, Ctrl, Alt, and Caps Lock do not produce characters on their own, but change the function of other keys when pressed together with them. There are also function keys (F1 through F12), navigation keys for cursor movement, and numeric keypads on the right side of larger keyboards.

Character layouts

The most common layout is QWERTY, named after the first five letters of the top row on the left. Different countries use variations, such as AZERTY (French) and QWERTZ (German). There are also alternative layouts such as Dvorak, designed to minimize finger movement. Non-Latin languages such as Arabic, Russian, and Chinese have their own methods, either with keys marked for those scripts or dedicated input methods.

Internal technology and connection

Keyboards sold commercially use different technologies. Membrane keyboards are made of thin film that makes contact when pressed; they are inexpensive and light. Mechanical keyboards have individual switches under each key, providing tactile feedback and longer durability. Connection to computers can be through a USB cable, or wireless technologies such as Bluetooth and radio frequencies. Older computers used different methods such as PS/2.

Touchscreen keyboards and modern devices

Most smartphones and tablets use virtual keyboards that appear on the touchscreen. These systems incorporate predictive text and spelling correction. When extended typing is needed, physical keyboards remain in use, as their tactile feedback and accuracy are generally superior.