I want to try this...but either im a noob or i'm too old...but what does he/she means by "driver" ?

If you read the build link the author says this...
"I discovered El Wire online, which is an electroluminescent wire that has the appearance of neon and comes in different colors and thicknesses. The wires need to be powered by a driver to work, and that driver can be powered by batteries or a power supply. Drivers come in different types, and you can also use sequencers to get some serious blinking action going. I opted to use a sound activated driver, which can pulse the wires on and off to whatever music or other noise is going on in the room."What is a driver? Is that what it is called or is that a nickname for whatever he/she is talking about?
I know if i walk into a hardware store or radio shack...and ask for driver, Im going to get a dumb look or either a smart arse "straight or phillips" answer?
I'd love to try to tackle a Super Mario Question block....sheesh i got enough scrap wood from my cab build I could build a whole Mario level!