Yes it has to do with having multiple windows open, it could be within the same application or different ones. For instance: Lets say I open up Xcode and want to start writing an application. I get stuck, need help and open up the Help documentation to look at example programs. I then have to switch back and forth between Xcode, to write the sample application, and the documentation, to see how to write the sample application. Since that gets annoying fast, I instead could creatively position Xcode to where it doesn't overlap the help documentation or i could "pin" the documentation's window of the sample Xcode program over Xcode. So while I actually have Xcode selected and am typing in code, the documentation window is actually my foremost window yet Xcode's window has an active focus reticle.
All I'm doing is bringing a window to the foremost view, but may or may not want it to be the application I'm working on.
Message was edited by: Syngian