A carbon-arc lamp is a type of lighting device that utilizes a pair of carbon electrodes to produce light. It operates by creating an electric arc between the two electrodes, which causes carbon to vaporize and emit a bright, intense light. The symbol combination "💡🔋🔦" represents the concept of using electrical energy stored in a battery (🔋) to power a portable light source (🔦), ultimately symbolized by a lightbulb (💡).