The settlement of various tropical islands between 1500 and 1900 involved a variety of different linguistic influences from the various settlers' country of origin. To assist communication, a 'user-friendly' style of language evolved, native to none, but understood by all - this is Pidgin. From there, any specific language that evolved in one particular territory was known as a Creole, so the second evolved out of the first. That's the difference between them.