Overt prestige: the standard usually has overt prestige; it is generally socially acknowledged as ‘correct’ and therefore valued highly among all speakers of the language.
Covert prestige: Non-standard varieties are often said to have covert prestige ascribed to them by their speakers. A specific, small group of speakers shows positive evaluation of and orientation towards a certain linguistic variety, usually without the speakers' awareness. The variety is usually not accepted in all