Apple today announced the latest version of OS X, Yosemite, at its Worldwide Developers Conference in San Francisco, CA with a brand new user interface designed for clarity and utility, iCloud Drive and improved continuity between iOS devices and Mac



From MacRumors:

Continuinity is the biggest new feature of OS X Yosemite, improving the connection between Macs and iOS devices. AirDrop now allows users to share items between iOS devices and Macs. Handoff is a new feature that allows devices near you to recognize when you're using a Mac. For instance, it allows users to answer phone calls to their iPhone on their Mac, instantly start a Hotspot from your iPhone and allows users to see "green dot" conversations on their Mac. The new UI is very similar to the flat look of iOS 7 with translucent windows, a new dock and app icons and an all-new notification center with a Today pane and both first- and third-party widgets like Weather and SportsCenter.

  Apple Announces OS X Yosemite with Improved iOS and Mac Connectivity and New UI