A filament light bulb is just another name commonly used for the vintage Edison light bulbs. Those reproduction bulbs are made to look like the original Edison bulb created over 100 years ago. The word Filament itself refers to the wire or thread inside the bulb which lights up when you turn it on. Hear are some of the names manufactures and consumer use to call those bulbs; Filament bulbs, Edison Bulbs, Antique Bulbs, Vintage Bulbs, Nostalgic Bulbs, Original Bulbs, Squirrel Cage Bulbs, old fashioned bulbs, and retro bulbs. All those names mean the same thing! There are also different shapes and sizes those bulbs come in. Globe, Tubular, Radio, Standard, and Edison are some of the shapes.