What is a language header?
The language header is sent along to the server by the browser. Usually the language header is the same as the language of the operating system of the visitor. When loading the website, the server can determine whether to load a page in a different language, depending on the specified language of the visitor.
The language header is specified in the client header. The name of the header is
Accept-Languageen-US;en if the browser of the visitor's operating system is in the English language.