Gas fireplaces commonly offer two types of ignition: millivolt (standing pilot) and electronic ignition (pilotless). Millivolt ignition maintains a small pilot flame continuously, ensuring reliable operation even during power outages, and works well with thermostats, wall switches, or remotes. Electronic ignition lights the burner only when heat is needed, which saves fuel and energy but may require electricity or battery backup. Your choice depends on preferences for convenience, efficiency, and backup operation.