What is an e-ballast?

[julescity]

To reduce cost in the electricity, try using lights with electronic ballasts.

hi, total newbie here, just set up my first planted tank. What's an e-ballast? What does it do? I bought a 36W light from NA without knowing what the e-ballst does....

[tawauboy]

a ballast is a device used to transform the electrical mains of 240v to about 1000v to 'fire' a fluorescent light tube.
two types of ballast are available; magnetic core and electronic ballast (e-ballast). magnetic core ballast has been around for a long time and cheap. e-ballast is a newer technology, lighter in weight, runs cooler, cost more but saves about 30% electricity.