Menu items on Windows can have 2 shortcuts - a keyboard shortcut like the macOS equivalent, that can activate the item when the menu is closed, and an access key, that can be used to activate it when the menu has keyboard focus. See https://learn.microsoft.com/en-us/previous-versions/windows/...

(The access key concept applies to many other types of control. Anything with a text label can have one, pretty much.)

The shortcut is indicated towards at the side of the menu bar, like macOS. The access key is indicated by an underlined letter. For example, in Firefox, the File > Save Page As... menu item has a shortcut key (Ctrl+S), and an access key (A). The A in As is underlined to indicate the access key, and there's a right-aligned Ctrl+S in that row of the menu bar to indicate the shortcut.