Gate
Typically, a door that is outdoors.

General Protection Fault
An operating system fault that occurs whenever a program executes a command that the operating system considers dangerous to the operating system. When a GPF is generated, the program that generated the GPF is closed and control is returned to the operating system.

Global Unlock
A normally-open input that, when closed, generates a signal that unlocks all doors in the access control system.

Ground
1) An electrical connection with a ground potential point.
2) An electrical connection to a circuit's zero voltage reference point. See Earth Ground.