Ground Versus Neutral Wire
According to the terminology in the NEC, the "grounding" conductor is for the safety ground, i.e., the green or bare or green with a yellow stripe wire. The word "neutral" is reserved for the white when you have a circuit with more than one "hot" wire. Since the white wire is connected to neutral and the grounding conductor inside the panel, the proper term is "grounded conductor". However, the potential confusion between "grounded conductor" and "grounding conductor" can lead to potentially lethal mistakes - you should never use the bare wire as a "grounded conductor" or white wire as the "grounding conductor", even though they are connected together in the panel.
[Subpanels are a bit different - subpanels are usually fed neutral and ground separately from the main panel.]
Note: Do not tape, color or substitute other color wires for the safety grounding conductor. In the electrical trade, and in common usage, the word "neutral" is used for "grounded conductor". This FAQ uses "neutral" simply to avoid potential confusion. We recommend that you use "neutral" too. Thus the white wire is always (except in some light switch applications) neutral. Not ground.