The A refers to the bulb shape. A is for arbitrary and is the shape that we all think of when we envision a light bulb (C is for candle, G is for Globe, etc.) The number 19 designates the size.

Now that incandescent bulbs are on the way out, LED bulbs are a clear choice, but there are things to keep in mind when buying them. Originally hailing from Troy, Ohio, Ry Crist is a writer, a ...