Functionalism proposes that the translation process is guided by extra-linguistic factors, more specifically by the function of the translation. Chapter 2 reviews the theory of functionalism (based on Skopos theory, from the Greek skopos meaning “purpose”) and some basic notions associated with it, while also explaining how to apply them in translation practice and discussion. It addresses basic functionalist concepts: extralinguistic factors (also known as situational features) and how they shape both monolingual and translated texts; the translation brief and translation norms; changes in situational features, and how they influence and guide translation decisions; and the “lifecycle” of a commissioned translation. Examples and illustrations accompany the presentation. The chapter starts by considering the relationship between extra-linguistic factors and monolingual texts, progressing to translated texts and translation tasks.