Whats the difference bwtwn attenuator and pot ??

I have been trying to find the best volume control I can for my SA-5000 preamp. The stock one is a carbon potentiometer. The Counterpoint website recommends the replacement of the cheap carbon pot that was stock with the unit and recommends the TKD CP-2511 conductive plastic as it will fit right in the unit. After checking with a few modifiers, they all agree that this TKD CP 2511 pot sounds great. The larger stepped attenuators by TKD and Goldpoint are way to big to install without moving the circuit board.

I came across another option by TKD that should fit in my preamp model 2P 2511 S. The information says this is a series step attenuator. They also make a non S version so there are no clicks/steps.

My question is, so what is the difference except for the $75 additional cost for the 2P versus the CP.

Here are some website links:

TKD-1

TKD-2

TKD-3

Thanks and Happy Listening