After using OS X Yosemite for a while, do you notice any changes in the design?
Fullscreen/Maximize with green button on Mac OS X Yosemite
Upgrade Mac to OS X Yosemite
How to see what’s new in OS X Yosemite
Click “What’s New in OS X Yosemite” from “Help” in the top menu of Finder. OS X Yosemite The page “Everything has the ability to look as good as it looks” is displayed.