Version 10.10 of the Mac OS X operating system. Introduced in 2014, Yosemite followed the "flat" look of the user interface design in iOS 7 (Apple's mobile OS Version 7). The system font changed from Lucida Grande to a thinner Helvetica Neue.
The Mac Dashboard is disabled by default (it can can be re-enabled), and in place of the Dashboard, a Today tab was added in the OS X Notification center where stock quotes, calculator, weather and other widgets can appear. The Spotlight search was enhanced with more categories, including the Bing search engine, and the input box displays in a window rather than affixed to the menu bar.
Enhanced Mobile Integration
Yosemite also added more integration with iCloud as well as iOS 8 devices. For example, AirDrop supports data transfers from an iPad to the Mac via Bluetooth LE or Wi-Fi, and the Mac can be used as a speakerphone when making calls on an iPhone. In addition, iPhone calls and SMS text messages can be sent and received on the Mac. See Mac OS X
and iOS versions
The "Flat" Look
Yosemite resembles Apple's iOS 7 user interface, in which icons and toolbars are less sculpted than previous Mac OS X versions. To keep up-to-date, Yosemite's energy saver icon became an LED bulb instead of the compact fluorescent (CFL) in Mavericks.