C120

I have just acquired a Smith & Wesson revolver. On the barrel it says "38 S&W Special". According to the box, it is model 36-1.

According the the guy at the gun shop this is a 38 Special and I need to buy 38 Special ammo. I've talked to the folks at Smith & Wesson and they say I need to buy 38 S&W Special ammo. I know there is also a 38 S&W.

Experts (please no guessing), is there a difference between 38 Special, 38 S&W Special, and 38 S&W?

Thanks.