This document discusses key concepts in linguistics, including: 1) It introduces the concepts of langue and parole, which refer to language as an abstract system and concrete usage respectively. 2) It also discusses the distinction between signifier and signified, and synchronic vs diachronic linguistic analysis. 3) The document provides an overview of phonology and syntax, explaining that phonology studies the phonic components of words, while syntax analyzes sentence structure and grammatical relationships.