Before updating to mavericks
During a keynote on October 22, 2013, Apple announced that the official release of 10.9 on the Mac App Store would be available immediately, and that unlike previous versions of OS X, 10.9 would be available at no charge to all users running Snow Leopard (10.6.8) or later.
This is to increase performance and cross-platform compatibility.
Some older Macintosh computers won’t run the latest version of OS X.
For example, the 2006 Mac mini “Core Duo” 1.83 will only run up to System 10.6.8, while the the 2008 Apple Mac Book Air will only run up to 10.7.5.
This means, if you don't have Snow Leopard and the Mac App Store you'll be unable to upgrade to Yosemite until Snow Leopard has been installed.
OS X Mavericks (version 10.9) is the tenth major release of OS X (now named mac OS), Apple Inc.'s desktop and server operating system for Macintosh computers.
OS X Mavericks vs OS X Yosemite: What's the difference?
During its 16 October special event, Apple announced that OS X Yosemite is coming out today, so you'll be able to download it any minute now.Of course, the real question is: What does Yosemite give me that Mavericks doesn't?Apple has introduced lots of new features, and you can find out all about them in our various Yosemite articles by following the links below.For most users the reasons to install mac OS Sierra outweigh the drawbacks, but for there are still some important reasons to wait — even for smaller updates.Apple just announced mac OS High Sierra at WWDC 2017 in early June.
Search for before updating to mavericks:
This is prompting more users to install mac OS Sierra even though it is not a required upgrade.