how to update your mac os 10.9.5 to 10.10.5

Apple Announces OS X Yosemite, Apple Inc.

Xcode 6 adds new programming language designed for game app developers and multimedia data manipulation and sharing.

iPhone Calls can be made from the OS X desktop.

Instant Hotspot makes using your iOS 8+ iPhone for network connectivity as easy as connecting to a Wi-Fi network.

Handoff lets you start an activity on one device and pass it to another OS X 10.10 or iOS 8+ device.

Mail handles large attachments more intuitively, allows PDF annotating, and includes Mail Drop for quick emailing of messages with attachments, where the attachments get encrypted in iCloud instead of sent via email.

Safari updated, UI simplified, default search changed to Bing from Google, added Private Browsing mode and DuckDuckGo search.

Also, has a Windows and Web-based interface

iCloud Drive adds Apple-branded Finder-integrated cloud storage, similar to DropBox and Google Drive.

Today view in Notification Center - provides a single location for all of the current day's events and items.

Spotlight is more tightly integrated into Application data and provides its own viewing interface - for both local and web-based sources.

Flattened 3D interface and presented a darker 'night theme' and translucent iOS 7-like elements.

With this release of OS X, Apple also instituted a public beta program by sign-up, seeded in the summer of 2014.

OS X Yosemite was announced on June 2 at the 2014 Worldwide Developers Conference, and was released to the public on October 16, 2014, as a free update through the Mac App Store. OS X version 10.10, also known as ' Yosemite', is the eleventh major release of OS X, Apple Inc's desktop and server operating system for Mac computers.

How to update your mac os 10.9.5 to 10.10.5