1) Battery Powered L.E.D : Easy to replace as uses AA batteries.
Advantages include the bulbs not getting warm, and as there is no mains electricity, it is safer than bigger lights.
2) Mains L.E.D : Comes with ‘barn doors’ and can be used with a scrim or gel, to either defuse the light or change the colour.
3) Cool Lights : Largest light, comes with a cover to soften the shine. Hazardous as it contains mercury, and there are lots of leads with provide potential dangers. Used as key lights, or side lights.