Itunes 12.1.2.27, macbook air, Doesn't quit and doesn't recognised just iphone6 plus ios 8.1.2.

Hi Chalmita,

For your immediate issue of the MacBook Air not shutting down, try the following:

OS X Yosemite: Log out, sleep, restart, and shut down
https://support.apple.com/kb/PH18786?locale=en_US

Hold down the power button until you see the restart, sleep, or shut down dialog, then click Shut Down, or press Return.

If you don’t want the app windows you currently have open to reopen when you restart your Mac and sign in, deselect “Reopen windows when logging back in.”

If your Mac won’t shut down, press and hold the power button for 5 seconds to force a shutdown.

Important: If you force a shutdown, you may lose unsaved changes in open documents.

The Mac is completely shut down when there is a black screen, no active power light, and no fan or drive noise.

What version of OS X do you have on your Mac? It might be helpful to back up your computer with Time Machine and update to the latest version, which is 10.0.3. Do the same with your iPhones so that everything is up to date.

Update OS X and App Store apps on your Mac - Apple Support
https://support.apple.com/en-us/HT201541

Update the iOS software on your iPhone, iPad, and iPod touch - Apple Support
https://support.apple.com/en-us/HT204204

Cheers!

- Judy