A designated key -- usually the F1 function key -- used to request help on the current context. Some keyboards have a dedicated "Help" key that may take the place of F1. In OSF/Motif applications, the help key is enabled by adding a "help callback" to a widget.
A particular key on the keyboard that is linked to the help system of a software program. Most Windows applications on a PC have standardised on the F1 key as the help key. Just press this key at any time and the software will display explanatory text that should help you understand the function or command you are puzzling over
In the SP graphical interface, the key that gives you access to the SP graphical interface help facility.