Language varies according to several factors, with region being a major parameter. Region leads to the development of dialects, which are regional varieties that differ in pronunciation, accent, rhythm and style but not grammar or vocabulary. The more a language spreads geographically, the more dialects it develops. For example, English has many national varieties like British English and Indian English due to being used in different countries and regions. Within countries there are also regional dialects, as seen with the many dialects of English that have developed within India.