Welcome to the forums k2,
Those are the allowable values of power that come from the wall. North America uses a 120v setup, Japan 100v, and Europe the 200-240 (usually 220) Instead of having 3 different PSUs with 3 different boxes that are identical besides the plug, they make it so it can work in any country and then just print the manual in 437 different languages. If you're PSU has a little red switch on the back, you'll have to select 115 or 230 based on what comes out of the wall. If there is no switch, then the PSU will detect the power coming from the wall and make the adjustments it needs. That's called Active PFC (Power Factor Correction) and is much better than the red switch.