What is an Arc-Fault?
An arc-fault is when electricity is discharged unintentionally. Regular arcing can happen when switches are turned on, appliances, or with items that have motors. Dangerous arcing is when items are not wired correctly; insulation is worn, pinching wires on the stud during the building process, or when a drywall screw or nail goes through a wire.

What does the arc-fault breaker do?
The arc-fault breaker acts as a protection device for the circuit. If there are any potentially dangerous arcs that occur on this circuit, the breaker will trip protecting the circuit to help prevent any fire or electrocution hazard.

Where should I have them?
The most standard place that arc-fault breakers are recommended would be in the bedrooms.