Page Level: By using the page directive on each content page to bind it to a master page
APPLICATION Level: By making a setting in the pages element of the application's Web.config file. All the specified ASP.NET pages (.ASPX files) in the application will be AUTOMATICALLY bind to a master page.
Folder Level: This strategy is used to bind at the application level, except that you make the setting in a Web.config file in ONE folder only. Here, master-page bindings are applied to all the ASP.NET pages in that folder.