Arc discharge is a phenomenon that occurs when an electric current passes through the air or another gas, creating a conductive path. This process generates a bright, intense light and high temperatures, often seen in devices like arc welders or lightning. The discharge happens when the voltage is high enough to overcome the insulating properties of the gas. During arc discharge, electrons are stripped from gas molecules, forming a plasma. This plasma allows electricity to flow freely, resulting in a continuous arc. The energy released can be harnessed for various applications, including plasma cutting and neon lighting.