need help unerstanding what sps3 is......

I'm pretty much a newb and trying to learn all I can. I have no idea what a sps3 is. Is it an app? Do I need to download it or is already on my phone? And how do I find its location on my Behold (or my computer). What is its function?
The reason I need to know is I am having trouble with seeing my phones files with TKexplorer. I have installed TKexplorer and Samsung USB driver. I have my usb setting on PC studio. My phone is connected (used Com3) and yet there are no files listed under Phone (P:). I have double clicked on it and nothing. On the bottom it says 0 items. I have tried different usb ports and turned the phone and computer off and on. The only thing I haven't done is update sps3 because as I said before, I don't know what that is.
Any help would be greatly appreciated.

Renee