.LEDs got their start as indicator lights for circut boards and small equiptment. Early specimens were very durable, had a relatiely low lumens output and accordingly were very energy efficient. Over time LEDs have become brighter and more reliable. Second generaion LED technology included the ability to string multiple LEDs into a single circuit. Over time , LEDs became more suitable for outdoor use. Accordingly, they were exponentially adopted by muncipalities as a replacement for incandescent bulbs in traffic lights. LEDs also saw limited success replacing flourescent bulbs and neon street signs. Todays LED technology is used extensively for  commercial,industrial and residential applications.LEDs capabilities have increased across the board; increases in lifespan, increases in brightnesss (performance), and increases in energy  efficiency. The greatly expanded use of LED technology has led to the development of warranties, industry best practices, and the introduction of government programmes