Grand

The potential that serves as the reference level for the ground. Usually, this potential is considered zero, and the potentials in an electric circuit are expressed relative to it. In electrical and electronic devices, it refers to a terminal used for grounding (earthing). Grounding is important for protecting against malfunctions and electric shocks by discharging abnormal voltage to the earth when a device becomes charged due to external surges such as external surges. Grounding may also be used as a return path for signal lines.