Spark discharge is a phenomenon where a sudden release of electrical energy occurs, creating a visible spark. This can happen when there is a buildup of electrical charge in an object, such as during a thunderstorm or when rubbing certain materials together. The discharge occurs when the electric field strength exceeds the breakdown voltage of the surrounding medium, typically air. This process is commonly observed in everyday life, such as when touching a metal object after walking on a carpet, resulting in a small shock. Spark discharge is also a critical concept in fields like electrical engineering and plasma physics, where it is studied for various applications, including lightning and spark plugs.