This chapter examines the terms 'pidgin' and 'creole' and the complications that arise from efforts to arrive at precise definitions of them, specifically with regard to determining which speech varieties are pidgins and creoles. Languages whose name contains Pidgin or a variant thereof are regionally restricted to the Pacific and to West Africa, and have English as the source of their lexicon. Languages that are called 'Creole' by their speakers are spoken on both sides of the Atlantic and include English-lexified Creolese in Guyana and Krio in Sierra Leone. Loreto Todd recognized that the term pidgin was variably used to designate makeshift contact varieties as well as fully stabilized languages. The most widely studied cases of pidgins and creoles all emerged from contact situations resulting from European colonial expansion. DeCamp proposed the creole continuum model, and Bickerton and Rickford refined and expanded upon it.