A creole language, or simply creole, is a stable natural language that develops from the process of different languages simplifying and mixing into a new form (often a pidgin), and then that form expanding and elaborating into a full-fledged language with native speakers, all within a fairly brief period.

That traditional idea is that things start with a pidgin, which Wikipedia describes as "a grammatically simplified means of communication that develops between two or more groups of people that do not have a language in common: typically, its vocabulary and grammar are limited and often drawn from several languages"