The brown wire in a plug is typically the live wire or hot wire. It carries the electrical current from the power source to the device you are plugging in.

Here's a breakdown of the common wire colors in a plug:

* Brown (or red): Live wire (hot)

* Blue (or black): Neutral wire

* Green/Yellow (or bare copper): Earth wire (ground)

Important: Always treat the brown wire as live and potentially dangerous. Never touch it directly, especially when the power is on.