What is the difference between "goodbye" and "bye-bye" and what do they mean to each other? What are the different meanings of "bye-bye" and "goodbye"?

Good-bye is a Chinese word, is a traditional Chinese etiquette, bye-bye is translated from English, also means good-bye, however, because it is a foreign translation, some fashion, some romantic feeling, the general young people use more, informal occasions use more. Good-bye is more formal and traditional. In fact, the difference between the two will slowly narrow over time.