This document discusses key concepts in translation studies including polysystems, pragmatics, semiotics, and sociological approaches. It provides definitions and explanations of these concepts. For polysystems, it describes how different literary genres compete within a system and how translation fits within this. For pragmatics, it discusses speech acts, implied meaning, and relevance in translation. For semiotics, it covers structural and interpretive approaches. And for sociological approaches, it notes how social theories can provide perspectives on translation as a social phenomenon.