page_title: Alt key
section_title: Evolution
hierarchical_section_title: Alt key / Evolution
caption_attribution_description: Čeština: Klávesa Alt na bezdrátové klávesnici Apple. English: The alt (option) key on an Apple wireless keyboard.
context_page_description: The Alt key Alt on a computer keyboard is used to change the function of other pressed keys. Thus, the Alt key is a modifier key, used in a similar fashion to the Shift key. For example, simply pressing "A" will type the letter 'a', but holding down the Alt key while pressing "A" will cause the computer perform an Alt+A function, which varies from program to program. The international standard ISO/IEC 9995-2 calls it Alternate key. The key is located on either side of the space bar, but in non-US PC keyboard layouts, rather than a second Alt key, there is an 'Alt Gr' key to the right of the space bar. Both placements are in accordance with ISO/IEC 9995-2.
  The standardized keyboard symbol for the Alt key, ⎇ is given in ISO/IEC 9995-7 as symbol 25, and in ISO 7000 “Graphical symbols for use on equipment” as symbol ISO-7000-2105. This symbol is encoded in Unicode as U+2387 alternative key symbol. Macintosh keyboards equate the Alt key with the ⌥ Option key, which has its own, related, symbol.
  The Alt key should not be confused with the Altmode key on some Teletype and ASCII terminals, which is a synonym for the ASCII escape character.
context_section_description: The Alt key has come to replace the Meta key of the old MIT keyboards.  In their original function, both Alt and Meta would set the high bit of the signal generated by the key to 1 (for example, A generates 01000001 while Alt+A generates 11000001). However, in modern software, due to the requirement of the high bit for internationalization, Alt no longer works in such a way.
  Since the 1990s Alt has been printed on the Option key (⌥ Opt) on most Mac keyboards. Alt is used in non-Mac software, such as non-macOS Unix and Windows programs, but in macOS it is always referred as the Option key. The Option key's behaviour in macOS differs slightly from that of the Windows Alt key (it is used as a modifier rather than to access pull-down menus, for example).
caption: The Alt key on an Apple keyboard
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