Here's why:

* Wide Prong (Neutral): The wide prong on a standard three-prong electrical plug is connected to the neutral wire, which is typically white.

* Narrow Prong (Hot): The narrow prong is connected to the hot wire, which is usually black.

* Round Prong (Ground): The round prong is connected to the ground wire, which is typically green or bare copper.

Important Note: Always be careful when working with electrical wiring. It's best to consult a qualified electrician if you're unsure about any aspect of electrical work.