which is the fn key on a mac
Fn key Apple also place the Fn key at the bottom left of the keyboard, displacing and shrinking the left Control key, though this is less controversial as macOS, the main operating system for most Apple laptops, is much less reliant on the Control key for shortcuts and modifiers than Windows or Unix-like operating systems.
AltGr key AltGr (also Alt Graph, or Right Alt[1]) is a modifier key found on some computer keyboards and is primarily used to type characters that are unusual for the locale of the keyboard layout, such as currency symbols and accented letters. On a typical, IBM-compatible PC keyboard, the AltGr key, when present, takes the place of the right-hand Alt key. In macOS, the Option key has functions similar to the AltGr key.