The issue: spinning beach ball
The spinning color wheel – People call it the Spinning Beach Ball of Death, or the Rainbow Wheel. Wikipedia calls it the Spinning Pinwheel, and the official name for it is the Spinning Wait Cursor. If you’re having problems or you’ve got a slow Mac, you’ll be seeing that beach ball quite a bit
According to Apple’s Human Interface Guidelines, “the spinning wait cursor is displayed automatically by the window server when an application cannot handle all of the events it receives. If an application does not respond for about 2 to 4 seconds, the spinning wait cursor appears.” (WindowServer is the background process that runs the Mac OS X graphical user interface.) Which is to say, the beachball is there to tell you your Mac is too busy with a task to respond normally.
Hardware causes for spinning beach ball
The most basic reason the beach ball appears is because your Mac’s hardware can’t handle the software task at hand. It’s not unusual to see the occasional beach ball when you Mac is performing complex computing tasks. Even everyday activities—such as syncing with iTunes—can temporarily overtax the CPU.
first steps to get rid of the spinning beach ball:
Consider adding more RAM or freeing up some hard disk space – OSX alone will need approximately 10-20GB of free disk space (depending on your setup) to function normally. Also expect 2-4GB of RAM to be the minimum requirement just to run your operating system. Add more if you plan on using applications like Photoshop, Iphoto, Imovie etc.
Resources on apple.com:
OS X Mavericks: Increase disk space