Apple has released its new operation system, the next generation of the OS X series, the OS X 10.11 El Capitan. Though it was available for the public for a while now through the Apple Beta Software program, the full version was released on September 30.
There are so many changes, performance enhancements, and security updates that would be really long to list. If you are interested in all the features and updates you can read more here:
OS X El Capitan Review from iMore