Button usage on the CC2531 router

In reference to this:

The S1 button only changes the state of the green LED.

I’d like to know what it means. Does it mean the S1 button only turns on and off the green LED, without doing something else?
Before I try it myself it’s better to know what it does. Don’t want to mess things up. @Koenkk could you clarify that?

Also it would be nice to have the same section about buttons which we already have for the routers for the coordinator page too.

Could someone clarify this?

@koenkk you probably know that, right? Thanks