[jackhill/qmk/firmware.git] / docs / reference_glossary.md

# Glossary of QMK Terms

## ARM
A line of 32-bit MCU's produced by a number of companies, such as Atmel, Cypress, Kinetis, NXP, ST, and TI.

## AVR
A line of 8-bit MCU's produced by [Atmel](http://www.microchip.com/). AVR was the original platform that TMK supported.

## AZERTY
The standard Français (French) keyboard layout. Named for the first 6 keys on the keyboard.

## Backlight
A generic term for lighting on a keyboard. The backlight is typically, but not always, an array of LED's that shine through keycaps and/or switches.

## Bluetooth
A short range peer to peer wireless protocol. Most common wireless protocol for a keyboard.

## Bootloader
A special program that is written to a protected area of your MCU that allows the MCU to upgrade its own firmware, typically over USB.

## Bootmagic
A feature that allows for various keyboard behavior changes to happen on the fly, such as swapping or disabling common keys.

## C
A low-level programming language suitable for system code. Most QMK code is written in C.

## Colemak
An alternative keyboard layout that is gaining in popularity.

## Compile
The process of turning human readable code into machine code your MCU can run.

## Dvorak
An alternative keyboard layout developed by Dr. August Dvorak in the 1930's. A shortened form of the Dvorak Simplified Keyboard.

## Dynamic Macro
A macro which has been recorded on the keyboard and which will be lost when the keyboard is unplugged or the computer rebooted.

* [Dynamic Macro Documentation](feature_dynamic_macros.md)

## Eclipse
An IDE that is popular with many C developers.

* [Eclipse Setup Instructions](eclipse.md)

## Firmware
The software that controls your MCU.

## FLIP
Software provided by Atmel for flashing AVR devices. We generally recommend [QMK Flasher](https://github.com/qmk/qmk_flasher) instead, but for some advanced use cases FLIP is required.

## git
Versioning software used at the command line

## GitHub
The website that hosts most of the QMK project. It provides integration with git, issue tracking, and other features that help us run QMK.

## ISP
In-system programming, a method of programming an AVR chip using external hardware and the JTAG pins.

## hid_listen
An interface for receiving debugging messages from your keyboard. You can view these messages using [QMK Flasher](https://github.com/qmk/qmk_flasher) or [PJRC's hid_listen](https://www.pjrc.com/teensy/hid_listen.html)

## Keycode
A 2-byte number that represents a particular key. `0x00`-`0xFF` are used for [Basic Keycodes](keycodes_basic.md) while `0x100`-`0xFFFF` are used for [Quantum Keycodes](quantum_keycodes.md).

## Key Down
An event that happens when a key is pressed down, but is completed before a key is released.

## Key Up
An event that happens when a key is released.

## Keymap
An array of keycodes mapped to a physical keyboard layout, which are processed on key presses and releases

## Layer
An abstraction used to allow a key to serve multiple purposes. The highest active layer takes precedence.

## Leader Key
A feature that allows you to tap the leader key followed by a sequence of 1, 2, or 3 keys to activate key presses or other quantum features.

* [Leader Key Documentation](feature_leader_key.md)

## LED
Light Emitting Diode, the most common device used for indicators on a keyboard.

## Make
Software package that is used to compile all the source files. You run `make` with various options to compile your keyboard firmware.

## Matrix
A wiring pattern of columns and rows that enables the MCU to detect keypresses with a fewer number of pins. The matrix often incorporates diodes to allow for NKRO.

## Macro
A feature that lets you send multiple keypress events (hid reports) after having pressed only a single key.

* [Macro Documentation](feature_macros.md)

## MCU
Microcontrol Unit, the processor that powers your keyboard.

## Modifier
A key that is held down while typing another key to modify the action of that key. Examples include Ctrl, Alt, and Shift.

## Mousekeys
A feature that lets you control your mouse cursor and click from your keyboard.

* [Mousekeys Documentation](feature_mouse_keys.md)

## N-Key Rollover (NKRO)
A term that applies to keyboards that are capable of reporting any number of key-presses at once.

## Oneshot Modifier
A modifier that acts as if it is held down until another key is released, so you can press the mod and then press the key, rather than holding the mod while pressing the key. Also known as a Sticky key or a Dead key.

## ProMicro
A low cost AVR development board. Clones of this device are often found on ebay very inexpensively (under $5) but people often struggle with flashing their pro micros.

## Pull Request
A request to submit code to QMK. We encourage all users to submit Pull Requests for their personal keymaps.

## QWERTY
The standard English keyboard layout, and often a shortcut for other language's standard layouts. Named for the first 6 letters on the keyboard.

## QWERTZ
The standard Deutsche (German) keyboard layout. Named for the first 6 letters on the keyboard.

## Rollover
The term for pressing a key while a key is already held down. Variants include 2KRO, 6KRO, and NKRO.

## Scancode
A 1 byte number that is sent as part of a HID report over USB that represents a single key. These numbers are documented in the [HID Usage Tables](https://www.usb.org/sites/default/files/documents/hut1_12v2.pdf) published by the [USB-IF](http://www.usb.org/).

## Space Cadet Shift
A special set of shift keys which allow you to type various types of braces by tapping the left or right shift one or more times.

* [Space Cadet Shift Documentation](feature_space_cadet_shift.md)

## Tap
Pressing and releasing a key. In some situations you will need to distinguish between a key down and a key up event, and Tap always refers to both at once.

## Tap Dance
A feature that lets you assign multiple keycodes to the same key based on how many times you press it.

* [Tap Dance Documentation](feature_tap_dance.md)

## Teensy
A low-cost AVR development board that is commonly used for hand-wired builds. A teensy is often chosen despite costing a few dollars more due to its halfkay bootloader, which makes flashing very simple.

## Underlight
A generic term for LEDs that light the underside of the board. These LED's typically shine away from the bottom of the PCB and towards the surface the keyboard rests on.

## Unicode
In the larger computer world Unicode is a set of encoding schemes for representing characters in any language. As it relates to QMK it means using various OS schemes to send unicode codepoints instead of scancodes.

* [Unicode Documentation](feature_unicode.md)

## Unit Testing
A framework for running automated tests against QMK. Unit testing helps us be confident that our changes do not break anything.

* [Unit Testing Documentation](unit_testing.md)

## USB
Universal Serial Bus, the most common wired interface for a keyboard.

## USB Host (or simply Host)
The USB Host is your computer, or whatever device your keyboard is plugged into.

# Couldn't Find the Term You're Looking For?

[Open an issue](https://github.com/qmk/qmk_firmware/issues) with your question and the term in question could be added here. Better still, open a pull request with the definition. :)
Commit	Line	Data
7b0356d1	1	# Glossary of QMK Terms
3e3c3e2b	2
cb9e5915	3	## ARM
	4	A line of 32-bit MCU's produced by a number of companies, such as Atmel, Cypress, Kinetis, NXP, ST, and TI.
	5
	6	## AVR
7f7f7635	7	A line of 8-bit MCU's produced by [Atmel](http://www.microchip.com/). AVR was the original platform that TMK supported.
cb9e5915	8
	9	## AZERTY
	10	The standard Français (French) keyboard layout. Named for the first 6 keys on the keyboard.
	11
	12	## Backlight
	13	A generic term for lighting on a keyboard. The backlight is typically, but not always, an array of LED's that shine through keycaps and/or switches.
	14
	15	## Bluetooth
	16	A short range peer to peer wireless protocol. Most common wireless protocol for a keyboard.
	17
	18	## Bootloader
	19	A special program that is written to a protected area of your MCU that allows the MCU to upgrade its own firmware, typically over USB.
	20
	21	## Bootmagic
	22	A feature that allows for various keyboard behavior changes to happen on the fly, such as swapping or disabling common keys.
	23
	24	## C
	25	A low-level programming language suitable for system code. Most QMK code is written in C.
	26
	27	## Colemak
	28	An alternative keyboard layout that is gaining in popularity.
	29
	30	## Compile
	31	The process of turning human readable code into machine code your MCU can run.
	32
	33	## Dvorak
	34	An alternative keyboard layout developed by Dr. August Dvorak in the 1930's. A shortened form of the Dvorak Simplified Keyboard.
	35
d8e29b53	36	## Dynamic Macro
d8e29b53	37	A macro which has been recorded on the keyboard and which will be lost when the keyboard is unplugged or the computer rebooted.
3e3c3e2b	38
67cc5ceb	39	* [Dynamic Macro Documentation](feature_dynamic_macros.md)
cb9e5915	40
	41	## Eclipse
	42	An IDE that is popular with many C developers.
	43
7aaef162	44	* [Eclipse Setup Instructions](eclipse.md)
cb9e5915	45
	46	## Firmware
	47	The software that controls your MCU.
	48
	49	## FLIP
	50	Software provided by Atmel for flashing AVR devices. We generally recommend [QMK Flasher](https://github.com/qmk/qmk_flasher) instead, but for some advanced use cases FLIP is required.
	51
d8e29b53	52	## git
af37bb2f	53	Versioning software used at the command line
3e3c3e2b	54
cb9e5915	55	## GitHub
	56	The website that hosts most of the QMK project. It provides integration with git, issue tracking, and other features that help us run QMK.
	57
	58	## ISP
	59	In-system programming, a method of programming an AVR chip using external hardware and the JTAG pins.
	60
	61	## hid_listen
	62	An interface for receiving debugging messages from your keyboard. You can view these messages using [QMK Flasher](https://github.com/qmk/qmk_flasher) or [PJRC's hid_listen](https://www.pjrc.com/teensy/hid_listen.html)
	63
d8e29b53	64	## Keycode
7aaef162	65	A 2-byte number that represents a particular key. `0x00`-`0xFF` are used for [Basic Keycodes](keycodes_basic.md) while `0x100`-`0xFFFF` are used for [Quantum Keycodes](quantum_keycodes.md).
d8e29b53	66
cb9e5915	67	## Key Down
	68	An event that happens when a key is pressed down, but is completed before a key is released.
	69
	70	## Key Up
	71	An event that happens when a key is released.
	72
d8e29b53	73	## Keymap
	74	An array of keycodes mapped to a physical keyboard layout, which are processed on key presses and releases
	75
cb9e5915	76	## Layer
	77	An abstraction used to allow a key to serve multiple purposes. The highest active layer takes precedence.
	78
	79	## Leader Key
	80	A feature that allows you to tap the leader key followed by a sequence of 1, 2, or 3 keys to activate key presses or other quantum features.
	81
7aaef162	82	* [Leader Key Documentation](feature_leader_key.md)
cb9e5915	83
	84	## LED
	85	Light Emitting Diode, the most common device used for indicators on a keyboard.
	86
	87	## Make
	88	Software package that is used to compile all the source files. You run `make` with various options to compile your keyboard firmware.
	89
d8e29b53	90	## Matrix
cb9e5915	91	A wiring pattern of columns and rows that enables the MCU to detect keypresses with a fewer number of pins. The matrix often incorporates diodes to allow for NKRO.
d8e29b53	92
d8e29b53	93	## Macro
af37bb2f	94	A feature that lets you send multiple keypress events (hid reports) after having pressed only a single key.
d8e29b53	95
67cc5ceb	96	* [Macro Documentation](feature_macros.md)
cb9e5915	97
	98	## MCU
	99	Microcontrol Unit, the processor that powers your keyboard.
	100
	101	## Modifier
	102	A key that is held down while typing another key to modify the action of that key. Examples include Ctrl, Alt, and Shift.
	103
d8e29b53	104	## Mousekeys
	105	A feature that lets you control your mouse cursor and click from your keyboard.
	106
7aaef162	107	* [Mousekeys Documentation](feature_mouse_keys.md)
d8e29b53	108
cb9e5915	109	## N-Key Rollover (NKRO)
	110	A term that applies to keyboards that are capable of reporting any number of key-presses at once.
	111
	112	## Oneshot Modifier
c9178882	113	A modifier that acts as if it is held down until another key is released, so you can press the mod and then press the key, rather than holding the mod while pressing the key. Also known as a Sticky key or a Dead key.
cb9e5915	114
	115	## ProMicro
	116	A low cost AVR development board. Clones of this device are often found on ebay very inexpensively (under $5) but people often struggle with flashing their pro micros.
	117
	118	## Pull Request
	119	A request to submit code to QMK. We encourage all users to submit Pull Requests for their personal keymaps.
	120
	121	## QWERTY
	122	The standard English keyboard layout, and often a shortcut for other language's standard layouts. Named for the first 6 letters on the keyboard.
	123
	124	## QWERTZ
	125	The standard Deutsche (German) keyboard layout. Named for the first 6 letters on the keyboard.
	126
	127	## Rollover
	128	The term for pressing a key while a key is already held down. Variants include 2KRO, 6KRO, and NKRO.
	129
	130	## Scancode
dad79caf	131	A 1 byte number that is sent as part of a HID report over USB that represents a single key. These numbers are documented in the [HID Usage Tables](https://www.usb.org/sites/default/files/documents/hut1_12v2.pdf) published by the [USB-IF](http://www.usb.org/).
cb9e5915	132
	133	## Space Cadet Shift
	134	A special set of shift keys which allow you to type various types of braces by tapping the left or right shift one or more times.
	135
03ad6927	136	* [Space Cadet Shift Documentation](feature_space_cadet_shift.md)
cb9e5915	137
	138	## Tap
	139	Pressing and releasing a key. In some situations you will need to distinguish between a key down and a key up event, and Tap always refers to both at once.
	140
d8e29b53	141	## Tap Dance
af37bb2f	142	A feature that lets you assign multiple keycodes to the same key based on how many times you press it.
d8e29b53	143
67cc5ceb	144	* [Tap Dance Documentation](feature_tap_dance.md)
cb9e5915	145
cb9e5915	146	## Teensy
af37bb2f	147	A low-cost AVR development board that is commonly used for hand-wired builds. A teensy is often chosen despite costing a few dollars more due to its halfkay bootloader, which makes flashing very simple.
cb9e5915	148
	149	## Underlight
	150	A generic term for LEDs that light the underside of the board. These LED's typically shine away from the bottom of the PCB and towards the surface the keyboard rests on.
	151
	152	## Unicode
	153	In the larger computer world Unicode is a set of encoding schemes for representing characters in any language. As it relates to QMK it means using various OS schemes to send unicode codepoints instead of scancodes.
	154
67cc5ceb	155	* [Unicode Documentation](feature_unicode.md)
cb9e5915	156
	157	## Unit Testing
	158	A framework for running automated tests against QMK. Unit testing helps us be confident that our changes do not break anything.
	159
f02430b1	160	* [Unit Testing Documentation](unit_testing.md)
cb9e5915	161
	162	## USB
	163	Universal Serial Bus, the most common wired interface for a keyboard.
	164
	165	## USB Host (or simply Host)
	166	The USB Host is your computer, or whatever device your keyboard is plugged into.
585f1400	167
7b0356d1	168	# Couldn't Find the Term You're Looking For?
585f1400	169
bb53635f	170	[Open an issue](https://github.com/qmk/qmk_firmware/issues) with your question and the term in question could be added here. Better still, open a pull request with the definition. :)