Langue refers to the abstract linguistic system shared by all the members of a speech community. Parole refers to particular realizations of langue. Langue is the social, conventional side of language, while parole is individualized speech. Langue is the code, and parole is the message. Parole is the concrete manifestation of language either through speech or writing. Langue is the abstract knowledge necessary for speaking, listening, writing and reading. It is relatively stable and systematic, whereas parole is more variable and may change according to contextual factors. Langue and parole together constitute language.