Wikipedia
In contrast to specific languages that have "Creole" in their name, a creole language, or simply a creole, is a type or classification of language; in particular, a creole is a stable, natural language that has developed from a pidgin (i.e. a simplified language or simplified mixture of languages used by non-native speakers) that over time has become nativized by children as their first language, with the accompanying effect of a fully developed vocabulary and system of grammar.
The precise number of creole languages is not known, particularly as many are poorly attested or documented, but the list of creole languages shows that creoles exist around the world. About one hundred creole languages have arisen since 1500. These are predominantly based on European languages, due to the Age of Discovery and the Atlantic slave trade that arose at that time. With the improvements in ship-building and navigation, traders had to learn to communicate with people around the world, and the quickest way to do this was to develop a pidgin, or simplified language suited to the purpose; in turn, full creole languages developed from these pidgins. In addition to creoles that have European languages as their base, there are, for example, creoles based on Arabic, Chinese, and Malay. The creole with the largest number of speakers is Haitian Creole, with about ten million native speakers.
The lexicon, (or roughly, the base or essential vocabulary - run but not running) of a creole language is largely supplied by the parent languages, particularly that of the most dominant group in the social context of the creole's construction. However, there are often clear phonetic and semantic shifts. On the other hand, the grammar that has evolved often has new or unique features that differ substantially from those of the parent languages.