Power
Laser uses light to cut metal. Light is concentrated into a single point to be able to pierce and cut metal. Just think of a magnifying glass that can be used to focus sunlight into a single point and burn it. That’s how cutting with light pretty much works.
Fiber lasers are solid-state lasers used widely in laser marking and engraving machines. The major difference between a fiber laser and a CO2 laser lies in their ability to laser cut sheet metal.