By brolloh With every application running in it’s own window, your cursor can quickly break into a sweat managing all of them at once! We’re hoping these two tips will ease your pain ever so slightly.
Sometimes we find ourselves using two applications concurrently, perhaps we’re referencing text from Safari but our work and focus is with Pages? Browsing iTunes but working on a Keynote presentation? To scroll through albums in iTunes running in a window behind Keynote, you may think you have to click on iTunes to bring it to the front and scroll, but you needn’t!
OS X allows your cursor to stray outside of the focus application and into one thats peeking around the side, scrolling with your mouse or trackpad will work in that application too without coming to the front!

What happens if you can’t quite see that text you’re referencing behind Pages? Awkwardly manoeuvre the reference window then head back to Pages? No! Using a similar trick, you can move any background window you want.
Hold down the command button and click on the title bar of the background window, you’ll find that you can move it anywhere you want with your main application remaining in front.

We hope this proves helpful!
More soon!

Source: SquareCMD