AppleCare+, and its similar product AppleCare Protection Plan, are like insurance policies for your Apple product—iPhone, iPad, iPod, laptop, and the like. If you crack your screen on your iPhone, for example, having purchased its $79 AppleCare policy, the company will fix it for a nominal fee, saving you from having to purchase a whole new phone.
Until recently, you could only get your Apple product repaired though AppleCare in the same country where you bought it.
Now AppleCare+ is valid around the world. If you're on vacation and your device breaks, as long as you're in another country that sells AppleCare+ and your device is sold in that country, you can get it fixed there. Apple's new global coverage sure beats a traditional insurance policy, which will usually repair or replace your gadgets only after you return home.
Apple's FAQ on its AppleCare plans can be found at http://www.apple.com/support/products/faqs.html.