What is a 60w type A light bulb?

A 60 watt type-A light bulb is an incandescent electric light source; it operates with 60 watts of power and has the traditional bulb shape that is categorized as type A. Incandescent bulbs use a tungsten filament that glows when an electrical current runs through it.

The interior of the glass bulb is evacuated of air during manufacturing, then either sealed as a vacuum or filled with an inert gas, such as krypton or argon. Recent advances in light-emitting diode technology has led to the development of LED electric lights that retain the same type-A bulb shape, while consuming significantly less power and extending the lifespan considerably.