A Pod is a computer device from a company called Line6, which emulates most of the great old amp sounds, and you can plug it in to your home stereo, or the PA system, and whatnot. It is basically a way to fake any classic and modern guitar amp sound computer simulated that is. Doesn´t work for me on stage at least, and at home I have my ´56 Princeton at approx 4 1/2 watts, nothing to demolish the house, or the neighbors ears.....
I get it. That would help my son to get acceptable sound out of his practice amp while he's learning.