Editing Keyboard layouts (section)

==Logical layout==
{{main|Region-specific layouts}}

In the early days of computing, many so-called "[[ASCII keyboard]]s" contained circuitry that told the host computer which character was typed using ASCII. Such keyboards did not need to care what type of computer they were attached to, and computers did not need to care what type of keyboard the owner had purchased. This was typical with kit-based computers where the keyboard had to be bought separately and where there was no authorised keyboard supplier.

Modern keyboards instead transmit a numeric code indicating the position of the key on a the keyboard. These codes are called [[scancode]]s. The computer is free to interpret these codes however it wishes, although certain keys are treated specially by the [[keyboard controller]] circuitry within the keyboard, such as the [[modifier key]]s under the [[USB]] protocol, or by the hardware (in particular [[alternate action]] keys).

Due to the differing requirements of languages around the world, the keys on a keyboard are assigned different characters in for each country. The [[legend]]s—the letters, numbers and symbols printed on the keys—are country and language specific, but the scancodes sent by the computer are independent of what's printed in the keys. The computer interprets each scancode according to the logical layout selected on the computer, which is why operating system installers ask for or verify your choice of input language. The input language cannot be determined from the keyboard itself.

Typically the computer will also permit selecting between multiple layouts on the fly, either from a pull-down menu or a [[keyboard shortcut]]. This allows people to type in different languages using the same keyboard, by swapping between different input languages. Self-adhesive labels with alternative legends assist with using the same keyboard for more than one language.

===Changing keyboard layout===
For how to change layout in an environment, see the page for each such environment:

*[[Microsoft Windows#Changing keyboard layout|Microsoft Windows]]
*[[MacOS#Changing keyboard layout|macOS]]
*[[X Window System#Changing keyboard layout|X Window System]], used on [[Unix]] and [[Linux]] desktops