There are three main types of diglossia: classical diglossia, high/low diglossia, and regional diglossia. Classical diglossia involves a situation where the high variety is used in formal contexts and the low variety in informal settings. High/low diglossia refers to a division where one variety is used for prestigious functions and the other for everyday communication. Regional diglossia occurs when different varieties are used in different regions.

Examples of diglossia are:

Norwegian Bokmål and Norwegian Nynorsk

Tamil (which has 2 versions)

Mandarin Chinese and regional dialects of Chinese

French and Alsatian

car

Francis Britto has written:

'Diglossia' -- subject(s): Diglossia (Linguistics), History, Tamil language, Variation

Diglossia is a linguistic term that refers to the coexistence of two dialects or languages within a single speech community. Another term that can be used as a synonym for diglossia is "bilingualism," although the two terms are not entirely interchangeable as they refer to slightly different language phenomena.