|USB||Keyboard Help (7:117)|
Pressing the Help key usually brings up documentation in the current application. In others it could bring up configurable options or other alternate screen.
On the PC, the F1 key often does the same thing.
The Apple Extended Keyboard through Apple A1048 for the Macintosh has had the key. It has usually been located above the Delete key in the six-key nav cluster above the cursor keys. The Apple USB Keyboard had it instead on the Function row above the Clear key.
On the Commodore Amiga and Atari ST platforms, the Help key is in the cluster above the cursor keys. When a PC keyboard is used with the Amiga, Scroll lock is mapped to Help. However, in the Amiga emulator UAE, it is instead the End key that is mapped to Help. On Atari ST, Alternate+Help printed the screen to the printer (if connected). 
Some models in Atari 8-bit home computer series had a Help key as part of named function keys in the top row or on the right-hand side, often next to Start, Select and Option.