When people who speak different languages come into sustained contact, new varieties of language sometimes emerge. These are called 'contact varieties. This book deals primarily with contact varieties that have emerged in the Australia-Pacific region within the last 150 years as the result of colonialism. Although the focus is on two particular types of contact varieties, pidgins and creoles, other types are mentioned as well, including cindigenized varieties' and 'language shift varieties. Since all these terms are used in a variety of ways in the literature on language contact, I begin with some definitions.