What does international edition mean on a textbook?

I need to buy a textbook called Adolescence; 12th edition by John W. Santrock. The International edition seems to be significantly cheaper. What is the difference between that book and the U.S. ed if there is one. The International edition is in english but is there a huge difference?What does international edition mean on a textbook?
If it's international edition, that means that it was originally published for international use (e. g. India). The content is exactly the same as the US edition, but the publishers just found ways to cut corners to make publishing it cheaper so that it's affordable for people in those countries. Usually they are in paperback, but they are still good quality textbooks. I have bought several international editions of books and found them to be the same as the US equivalents. They are such good deals!What does international edition mean on a textbook?
my friend bought an international edition (of a different book) for much cheaper and he said it's because the international edition is made in China where they don't have to follow copyright laws and can print whatever. He said his book was the same thing, just much cheaper.