What does the acronym "LED" stand for?

The acronym "LED" stands for Light Emitting Diode. This term refers to a semiconductor device that emits light when an electric current passes through it. LEDs are widely used in various applications, including traffic signals, street lights, and electronic displays because they are energy-efficient, have a long lifespan, and can produce bright light in a range of colors.

Understanding the operational principles of an LED is essential for a signal technician, as these devices are integral to modern lighting solutions and signalling technology. The terms presented in the other options do not accurately represent the function or structure of a diode, emphasizing the importance of precise terminology in the field of electronics and signal technology.