Diglossia

In linguistics, diglossia ( /daɪˈɡlɒsiə/; Greek: διγλωσσία < δύο+γλώσσα, two languages) refers to a situation in which two dialects or usually closely related languages are used by a single language community. In addition to the community's everyday or vernacular language variety (labeled "L" or "low" variety), a second, highly codified variety (labeled "H" or "high") is used in certain situations such as literature, formal education, or other specific settings, but not used for ordinary conversation.