Apple is releasing OS X Yosemite today

Apple is releasing OS X Yosemite today, launching what is arguably the most significant update to the Mac's
operating system in years. Yosemite, which will be made
available for free in the Mac App Store, includes a total
visual overhaul of OS X that introduces a simple and
colorful style, much like what's found on iOS.
In fact, the reason Yosemite is so significant is that it
really begins to bring the Mac and the iPhone together
in a meaningful way. For one, you'll be able to start
answering phone calls and sending and receiving text
messages from your Mac. Apple demonstrated the phone
call feature at an event today by ringing up Stephen
Colbert, who held a brief conversation involving a lot of
code words with software chief Craig Federighi.
But the big feature here is that you'll be able to easily
move your work between your Mac, iPhone, and iPad,
with each device prompting you to pick up where you
left off on another: for instance, you might start writing
an email on your phone and then move to your Mac,
where you'll be able to finish the draft.
Like iOS, Apple has been moving toward delivering
annual updates to OS X. That means that each update
may only have a few notable features, but it's allowed
the operating system to advance at a much more rapid
pace. It's also helped advance Apple's goal of bringing
parity between iOS and OS X, with the desktop OS' last
several releases including comparable features such as
apps for Notes and Reminders.

Via : The Verge