An international driving permit (IDP) is an accepted form of identification in 150 countries worldwide. It contains your name, photo and driver information. It translates your identification information into ten languages, so it speaks the local language even if you don't. Most countries highly recommend carrying an International Driving Permit, even if you're not planning to drive, since it can help you communicate with authorities if needed.
Many countries require an IDP to drive legally, but it's not a driver's license. You'll need to have a valid, state-issued driver's license with you if you're planning to drive in countries that require and international driving permit. An IDP accompanying a U.S. driver’s license can only be issued in the United States—another country cannot issue an IDP to be used in conjunction with a U.S. driver’s license.
Since fines for driving without an IDP can be quite costly in the countries that require one, check local laws before you travel.