Three Main Types of Power Supplies
When referring to our lighting products, the power supply is the electrical component needed to power the lighting system. The lighting system could be incandescent (halogen or xenon), fluorescent, or LED.
Transformers are used to literally transform the voltage of the electrical current that is flowing from your outlet into your light fixture. Transformers typically output alternating current (AC) to low voltage incandescent lighting systems like Xenon or Halogen. Some LED products will use AC, but most require direct current (DC). This is when LED Drivers come into the picture.
LED Drivers supply the direct current (DC) power that some LED lighting systems require. It also regulates the current that flows through the LED itself and offers two different types: Constant Current or Constant Voltage.
Fluorescent Ballasts supply power to - you guessed it - fluorescent light bulbs. Many common household fluorescent bulbs (like the spiral-shaped ones that you stick in your table lamp) are "self-ballasted" which means that the power source - the ballast - is part of the light bulb itself. But for long fluorescent tubes, like the kind that you might find in your garage or closet, an external fluorescent ballast is used.