Simple--it's just a transformer.

"Wall current" is 120 volts AC, leds just want a few volts DC, like from a battery.

The driver just converts the AC to DC, like a wall wart does.

But leds need the current to be tightly controlled, so real led drivers have some kinda regulator built-in.

Transformer + Regulator = driver.

That simple.

We'll walk ya through building a light if you want. Can you solder?