元键 fn、control、option、command（mac）和 fn、ctrl、alt、win（windows）的定义是什么？

Question 1

IBM 定义了 Windows 键盘。首先是 IBM 84 键键盘，然后是 101 键键盘。这些键盘没有 Windows 键或上下文菜单键。这些功能的键用于F10菜单访问，Shift+F10用于上下文菜单。（Shift+F10在 Office 6 中引入，因为 Win 3.11 没有上下文菜单）。

Windows 95 和开始菜单的发布意味着开始菜单需要一个键。微软在键盘上引入了两个 Windows 键和一个上下文菜单键。它几乎只是实现了开始菜单。编辑 Ctrl+Esc是无键盘的开始菜单访问键Winkey。

在过去的 25 年里，这些键已经超载，几乎所有其他键（如果不是全部）都被应用程序使用。

看https://en.wikipedia.org/wiki/Computer_keyboard#Types_and_standards

这就是键盘上有什么键的原因。

至于他们为什么要这么做——通用用户访问 (CUA) 是操作系统和计算机程序用户界面的标准。它由 IBM 开发，并于 1987 年作为其系统应用程序架构的一部分首次发布。CUA 标准最初用于 MVS/ESA、VM/CMS、OS/400、OS/2 和 Microsoft Windows 操作系统，现在已在其他操作系统的程序中实现，包括 Unix 的变体。Java AWT 和 Swing 也使用它。请参阅https://en.wikipedia.org/wiki/IBM_Common_User_Access#Description。我曾在 VM/CMS、OS/2 和 MSDos/Windows 中使用过它。

看https://en.wikipedia.org/wiki/IBM_Common_User_Access#Description

至于为什么F4是F4https://devblogs.microsoft.com/oldnewthing/20180918-00/?p=99765

为什么Ctrl+ScrollLock与 escape 相同https://devblogs.microsoft.com/oldnewthing/20080211-00/?p=23503

为什么不应该使用Ctrl++Alt作为快捷方式https://devblogs.microsoft.com/oldnewthing/20040329-00/?p=40003

编辑2

为了让你们了解它的Winkey进化过程，以下是它所做的事情2003（我上次更新列表时）。请注意不同的团队 - 硬件团队（Microsoft 鼠标和键盘）、办公团队，以及来自 Windows 98 团队的一些个人程序员。

Key Description 
Winkey or Ctrl + Esc Opens the Start Menu. 
Winkey + A Older Intellitype: Opens Accessibility. 
Winkey + B Set focus to the first icon in the System Notification Area. 
Winkey + C Office XP: Correct text in speech recognition.
    Older Intellitype: Opens Control Panel. 
Winkey + D Minimises and hides windows that can't be minimised or Unminimises/unhides all windows. 
Winkey + E Starts Explorer. 
Winkey + F Starts Find Files or Folders. 
Winkey + Ctrl + F Starts Find Computer. 
Winkey + G Cycles through Gadgets in the Vista's Sidebar. 
Winkey + H Office XP: Handwriting recognition. 
Winkey + I Older Intellitype: Opens Mouse Properties. 
Winkey + K Older Intellitype: Opens Keyboard Properties. 
Winkey + L Lock Workstation or Switch User (if Welcome Screen is on).
    Older Intellitype: Logs off Windows. 
Winkey + M Minimises all windows that can be minimised. 
Winkey + Shift + M Unminimises all windows. 
Winkey + P Older Intellitype: Opens Print Manager. 
Winkey + R Starts the Run Dialog. 
Winkey + S Older Intellitype: Toggles Caps Lock. 
Winkey + T Office XP: Toggle speech dictation mode.
    Vista: Cycles through Taskbar buttons, Press Enter or Space to 
    activate a window. This is same as Winkey + Tab in older versions. 
Winkey + U Accessibility Utility Manager (Called Ease Of Access in Vista) 
Winkey + V Office XP: Toggle listening status of the microphone.
    Older Intellitype: Opens Clipboard Viewer. 
Winkey + X Vista: Opens Mobility Centre if Windows thinks you have a 
    mobile PC. Mobility Centre is included in many Vista editions but won't 
    run unless it thinks it is a mobile PC. 
Winkey + F1 Starts Windows Help (F1 start help for the current application, if the focus is in Explorer or the desktop F1 also starts Windows Help). 
Winkey + Tab Cycles through Taskbar buttons, Press Enter or Space to activate a window.
    Vista: Cycles through open windows using Windows Flip3D. Release keys to activate window. Pressing Escape cancels switching windows. 
Winkey + Ctrl + Tab Cycles through parts of the desktop and taskbar.
    Vista: Starts Windows Flip3D. Use Arrow keys, Tab, or Shift + Tab to navigate and Enter or Space to activate. Pressing Escape cancels switching windows. 
Winkey + Break Starts System Properties. 
Winkey + Space Brings Vista's Sidebar to the top.
    Older Intellitype: List Intellitype Hotkeys. 
Winkey + Alt + Enter Starts or switches to Media Centre's Start screen. 
Winkey + <a number> Computer specific function set by the computer manufacturer. Very few computers use this.
    Vista: Activates Quicklaunch icons. Winkey + 1 is the first icon, Winkey + 2 the second, etc. 
Winkey + Up or Down Arrow Keys Windows 98 Only: Changes magnification levels in Magnifier 
Winkey + Page Up Windows 98 Only: Toggles Colour Inversion in Magnifier 
Winkey + Page Down Windows 98 Only: Toggles Mouse Tracking in Magnifier 
Winkey + Ctrl + <a number> [0-5] In Vista's Photo Gallery (but not Media Player or Explorer) rates an item as 0 to 5 stars. Winkey + 0 doesn't work on my computer.

以下是 Wikipedia 的 Winkey 版本列表https://en.wikipedia.org/wiki/Windows_key

Answer