Set the Culture attribute in the @ Page directive in the .aspx file. When the page is requested, the dynamically generated class sets the value of this property. In addition, you can also explicitly set the value of the Page.Culture property programmatically or in the globalization element of the Web.config file.

The Page.Culture property is used to help localize page content. You can set it to any valid culture ID. For example, the en-us culture ID sets the page to American English, while the fr culture ID sets the page to French. You can also set the value to auto which will perform automatic detection of the browser's preferred language and set it. The automatic language detection can be qualified with a default value such as auto:en-us.

For more information, see the System.Globalization.CultureInfo class overview.