This document discusses Saussure's concepts of langue and parole and key linguistic concepts like linguistic signs, linguistic structure and relationships between elements. It explains that langue refers to the abstract rules and conventions of a language shared by a language community, while parole is the individual usage and performance of language. Language has a duality of structure - elements are selected based on paradigmatic relationships and combined based on syntagmatic relationships. Saussure emphasized the priority of synchronic analysis which describes a language system at a single point in time, over diachronic analysis of language changes over time.