Here's what it means:

* Neutral wire: Carries current back to the source (usually a breaker panel) after it has passed through a load (like a light fixture or appliance). It completes the electrical circuit.

* Ground wire: In a properly wired system, there's also a green or bare copper wire that acts as the ground wire. It provides a path for current to flow to the earth in the event of a fault, protecting you from electrical shock.

Important notes:

* Color coding is not universal. Always double-check with a multimeter or a qualified electrician to confirm the function of each wire.

* Never assume a white wire is neutral. Improper wiring can lead to dangerous situations.

Let me know if you have any other questions about electrical circuits!