Langue and parole is a theoretical linguistic dichotomy distinguished by Ferdinand de Saussure in his Course in General Linguistics.[1]
The French term langue ('[an individual] language')[2] encompasses the abstract, systematic rules and conventions of a signifying system; it is independent of, and pre-exists, the individual user. It involves the principles of language, without which no meaningful utterance, or parole, would be possible.
In contrast, parole ('speech') refers to the concrete instances of the use of langue, including texts which provide the ordinary research material for linguistics.[1]
Système de signes vocaux, éventuellement graphiques, propre à une communauté d'individus, qui l'utilisent pour s'exprimer et communiquer entre eux : La langue française, anglaise.