All of the above OS X operating systems are compatible with all Macs that are capable of running OS X Mountain Lion. That includes iMac models from mid-2007 or later, 13-inch aluminum MacBook models from late 2008 or later, 13-inch MacBook Pro models from mid-2009 or later, 15-inch and 17-inch MacBook Pro models from late 2007 or later, MacBook Air models from late 2008 or later, and Mac mini, Mac Pro and Xserve models from early 2008 or later. The models must also have at least 2 GB of memory (4 GB of memory or greater is much preferred), 8 GB of available hard disk space and Snow Leopard 10.6.7 or higher in order to install from the App Store. It is strongly recommended that you backup your computer hard drive to an external hard drive using Carbon Copy Cloner or SuperDuper. See the video links below:
How to Format an External Drive, Create a Bootable Backup Drive, Format a Hard Drive, SuperDuper Backup, and How To Use Time Machine for the Mac.
(Click on Windows Below)
SYSTEM REQUIREMENTS FOR INSTALLING OS X MAVERICKS, YOSEMITE, AND EL CAPITAN.