does Photoshop have anything like a "alpha to selection"

I need a bit of help!
As some of you might now I've been using gimp for a while
recently I have switched to Photoshop for a bit of a try out. What I want to know is does Photoshop have anything like a "alpha to selection" like what GIMP has?
It would select a region on the layer ( not the whole layer). it would select just the render, not the whole layer
hope that made sense to some one lol!

If you hold down the ctrl button, and click on the desired layer, it should make a selection of only the render (or whatever it is you have on the layer). If I'm understanding right, that should solve your problem, if not; then I have no idea what you're talking about. =P