Language contact refers to the interaction between speakers of two or more languages or dialects that influence one another. Contact linguistics is the study of language contact. It is common for languages to influence one another when speakers of different languages communicate closely. Code-switching, pidgins, mixed languages and creoles are the common products of language contact. In many other circumstances, contact between speakers takes place but the long-term impacts on the language are less obvious. Nonetheless, they may include loan words, calques, or other kinds of borrowed material. Language is characterized by variation, as there are multiple ways to say the same thing. Speakers can have different syntax, word choice, morphology and pronunciation. Variationist linguistics studies the effect of linguistic, social and individual factors to understand the choices which speakers of a language make while choosing between different variations of the same word. This book includes some of the vital pieces of work being conducted across the world, on various topics related to contact and variationist linguistics. It is a resource guide for experts as well as students.